Some of the focal lengths in that list are too close together or
superfluous: IMHO you can drop the 135  and (arguably) the 50mm. I'd
certainly go for a 24mm instead of a 28mm and also go for a 20mm
(Pentax's is quite good).

I've used the Pentax 35mm f/3.5 and found it excellent , the 200mm f/4.0
and found it mediocre.

If you happen to go for a screw mount system, you should also consider
some Zeiss Jena, Meyer, Steinheil, Schacht and Schneider lenses.

You'll probably get lots of tips for the K1000 - Why? I don't know (no
DOF preview among others).
The KM, K2, KX and others are cheaper *and* better.

The LX is a camera I'd certainly get if I went Pentax, but I haven't
actually used it, so others should comment here...

You might consider oggling through this web site:
<http://stans-photography.info/> It has a ton of info on most
Pentax-branded lenses, including a few best-of discussions.

As far as bodies, you're limited when it comes to mirror lock-up. Most
have DOF preview, and some have MLU. The standard reference:
<http://www.bdimitrov.de/kmp/>

The Pentax 35mm film bodies most often spoken of in hushed tones are the
aforementioned LX and the MZ-S. The new K10D looks to be another happy
addition to that list, but it's digital, so maybe that's not what you're
after.

The secret to good bokeh is to prevent bad bokeh. Control the contrast
in out-of-focus elements, or decide that you like it. :-)

I have a K2 and love it very much.  I think it is a bit oddly designed, it has aperture
priority which renders perfect exposures, the rest is manual.  It will not make use
of the "A" setting on lenses that have them, such as the "A" series which was later
made in the 80's, and still made these days.  That takes a program body.

The K2 does have mirror lock-up, is a large and tough body of brass and includes
depth of field preview, as well as exposure compensation (which I never use).

Three "bugs" that shouldn't be there, does not accept a motor unless it is a DMD
model, and no lighting of the match needle meter scale inside the viewfinder at
night, can't see it.  And the design of the ISO(ASA) dial 'around the mount' is odd
and hard to work, takes finger nails while depressing a lever.  The exposure
compensation is another ring around the mount but easy to work.  The camera is
worth having and using.

The KX has mirror lock-up, is essentially the same as the K2 but no aperture
priority. It's flash sync is 1/60 second, K2's is 1/125.  KX is more of an 'artistic
use' camera body, totally manual.  The KM is that same as that, no mirror lock up.  
And the same as the KM is the MX, only smaller, and takes a motor.

The K2/KX meter is silicon photo diode which was advanced for it's time and still
used these days, perfectly accurate so far.  At that time more advanced than Canon's
CDS meters which over-expose in lower light and use mercury batteries, not
currently available.

Good thing about the two cameras is that they use silver 1.5 volt batteries that are
still commonly available, my local radio shack has them at $3.49 each.

Or buy an LX, takes motors and winders, has mirror lock-up, and totally
professional. There were early and later models of LX with differences.  Same
batteries.  http://www.bdimitrov.de/kmp/  And I suggest, buy a film scanner.

... hope this helps,

I have a KX I am very happy with. MLU, depth-of-field-preview but no
spot metering (my another Pentax MZ5N has that). KX has a mechanical
shutter, battery drives just the light meter. KX is very well built and
intuitive to use( at the time (1975) it was built to be a professional
body in the Pentax line-up). A used KX is a LOT cheaper than a used LX.
MX would be another alternative but I find KX a lot better.
As for lenses I would try 28 mm F3,5, (or 35 mm f2,8), 50 mm f1,4 and
135 mm f3,5.

Väinö Louekari

Your question is stated too broadly to allow a precise response.  It is like
"Which is the best camera?"

Best for WHAT?

If you are looking for the lowest PRICE, then the screwmount SMC Takumars,
mounted on a Spotmatic F (assuming that you want full aperture metering) are
probably the best overall for your purposes.  But Spotmatics had no mirror
lockup or spot metering.  Mamiya made some M42 camera bodies with spot
metering, but they did not have full aperture metering.  No way you're going
to have it both ways.

There were a couple of Pentax models with MLU, but they were in the more
recent K-mount, and they were expensive.

You need to tell us which features you must have, and whether price or
features are most important, before we can give you an appropriate
suggestion.

Hmmm, best bokeh and sharp for these FLs.  Well, I haven't used all of the
options/versions for all of these FLs, but from what I have used, here's my
take:

Perhaps before I go on I should make sure you know what the K, A, etc.
appellations mean.  These are all K-mount bayonet lenses that I'm
describing, in chronological order.  You could, alternatively, use the older
screw-mount lenses and still get much of the benefit of the optics, but
these days I think the price differential used is so small that I'd probably
only consider the bayonet lenses and bodies (of course, if you get a really
good price on a screw-mount lens, you can still use it on a K-mount body
with an adapter, though you'll have to use stop-down metering.)

K - earliest version, metal, manual focus

M - optimised for compactness.  Some use the same optical formula as their K
predecessors, some don't.  Not all the lenses that exist in K (or A)
versions were also made as M versions.  Metal bodied.  Manual focus.

A - first lenses that support shutter priority and programme operation (it's
manual or aperture priority only with earlier lenses).  Some of these are K
or M designs with the 'A' feature added, others are new designs.  Several K
and M designs were 'tweaked' a little for the A versions.  Metal bodied.
Manual focus.

F - first lenses with AF.  A few changes from the A optical designs, but
mostly the same designs.  Some plastic, some metal.

FA - later AF lenses, the main changes are that more information is
exchanged between the body and the lens, on bodies that support it (KAF2
mount bodies).  Some changes from F optical designs in some lenses.  Some
plastic, some metal.

FAJ - designed for bodies that can set the aperture, no aperture ring on the
lens itself.  An abomination.  Plastic.

Then there are some lenses for the reduced sensor size digital bodies, and
some digitally optimised lenses that cover the full frame size.

Also, there are the Limited lenses: these have AF and can be compared to
luxury versions of the FA type: no holds barred optical designs and very
nice mechanicals.

And finally the * lenses - eg. A*, FA*, etc.  Originally this was those that
used ED glass types, and essentially now it is an indication of a somewhat
higher quality level, though * lenses don't exist for all FLs, since this
design isn't always necessary.  They have nice metal barrels (usually) and
for the AF ones there's a very nice AF/MF clutch mechanism that means that
the focus feel in manual is much better than is usual for an AF lens.

All these lenses have Pentax's SMC coating, but the coating has 'evolved'
over time, and in particular the A and later lenses seem slightly more flare
resistant than the earlier lenses - though the Ks are still more flare
resistant than a brand new Canon lens, so who's complaining?  >;-)  The
Limiteds have Pentax's "Ghostless" coating, which is a sort of
super-super-multicoating (this and their very good coma is one of the
reasons I find them particularly good for night shooting).

OK, so to specifics:

28mm - the f3.5K is, I think, the sharpest, and has nice bokeh.  The f2.8s
may be just behind the 3.5s for sharpness, but are at least their equal for
bokeh - and from f4 or 5.6 are indistinguishable on sharpness anyway.  Of
the f2.8s, I think the A is the best version I've used, but the FA is said
to be its equal or perhaps slightly better.

The 30mm f2.8K is probably sharper and with (even) better bokeh than any of
these 28s, but hard to find (no, mine isn't for sale!)  The 31mm f1.8 FA AL
Limited is sharper still, with nice bokeh and excellent coma, though for
bokeh per se, the 30mm is at least as good and probably my preference - I
need to do more testing really to tell apart these two lenses both of which
I like a lot.

35mm - the f2 supposedly has the best bokeh.  I have an f2M and it is nice,
but I wouldn't say it's necessarily any better than the f3.5K I have, which
I think is the sharpest.  The f2A may be better, but I've never used one.

50mm - well, of course here you are spoilt for choice.  None of the Pentax
50s is anything less than excellent, and even the ludicrously cheap f2 will
blow the doors off the much touted f1.8s of some other makers we won't
mention.  However, everyone seems to agree that the best is the f1.4A, and I
must agree that mine is indeed a very special lens.  The f1.2A possibly has
even better bokeh, and wide open a rather special look, but it is not as
sharp as the f1.4 until about f5.6, at which point I can't tell them apart
(though some people claim that they can).  The f1.7M is very nearly the
equal of the 1.4A, and will cost you a lot less.  The f2.8 A and FA macros
are also incredibly sharp - maybe the sharpest 50s you'll ever find - and
their bokeh is not all that different to the other 50s.

85mm - the f1.4s are said to have the best bokeh, with the A* being the best
for distance work (landscapes) and the FA* more optimised for portraits.  I
don't have either of those however.  The f2 has a bad reputation in some
parts, though I know people who have it and like it - maybe it's good, just
not as good as the other 85s.  The one I have is the f1.8K, and it is an
excellent lens, very compact and with attractive bokeh, good for people and
for landscape.  The f2.8F Soft-Focus is also really nice, and if you enjoy
portraits may be worth a look.  Don't overlook the 77mm f1.8 FA Limited
either, which may be the sharpest of all of these.

You've skipped the 105mm f2.8K which is a real cracker, and the 120mm f2.8M
which I think is a very undervalued lens these days.  Also the 100mm
macros - all are good but the absolute star is the 100mm f2.8 FA Macro: you
won't find a sharper lens, and its bokeh is very good indeed: better than
other macros I've known (some have awful bokeh) and certainly as good as the
much touted 90mm Tamron.

135mm - the 'star' has to be the f1.8A* ED, which is one of my favourites
and a great people lens.  But it is very heavy and has become expensive.
Nearly as good, very nearly as sharp and with similar bokeh, but lighter and
cheaper is the f2.5K (not the much cheaper Takumar which is a different
design, cheaper, and not SMC coated).  The f2.8 FA IF is very nearly as nice
as the f2.5K if you want AF (though it is a very ugly lens to look at, looks
like the army designed it.)  The f3.5 in all its versions is very cheap to
buy, very small and compact, and a good lens by anyone's standards, just not
quite up there with its f1.8 and f2.5 cousins.  The 150mm f3.5K is good
too - I like it more than the f3.5 135mm, and it is actually lighter than
the 135mm f2.5K.

200mm - the f4 macros have good reputations but I've never used one.  The
other f4s tend not be well thought of: they are not really bad lenses, but
they don't quite reach the standard compared to other Pentax mid-long
primes.  The 200mm that I prefer is the f2.8 FA* ED IF - this is remarkably
sharp and contrasty for a 200, and the bokeh is good.  Once you get beyond
about 135mm, bokeh often tends to become harsher with anyone's lenses, and
this 200 has bokeh _at least_ as good as anything else I've seen of this
length.

300mm - the f4K/M/A is a good lens, but I prefer a little more contrast.
This you get, along with sharpness and, for a 300, good bokeh, with the f4A*
and f4M*.  This (mine is the A* version) is my preferred 300 for
hand-holding and/or if bokeh is a key concern.  The f4.5F* ED IF is probably
a tiny bit sharper and is the lens I prefer for tripod use (or if I want AF,
of course) but I think the A* has slightly nicer bokeh.  The FA* is the same
optical design as the F*, but lacks the F*'s tripod mount, for some reason.

Phew - hope that's some use.  I didn't mention zooms since none really has
bokeh quite as nice as a fixed FL, and I'm writing enough as it is!

Most durable and best built body: I'd say the LX, or if you want AF, the
MZ-S.  I accidentally knocked the MZ-S against the corner of my house once,
knocked a bit of brick off the house, didn't even scratch the camera.

No spot-meter on the LX, but the best meter there is for long exposure work,
and the interchangeable finders are good.  Only the meter and shutter speeds
below 1/90 need the battery, so it's also good if power is a concern.  I
have five (including my trademark pink snakeskin one) and a spares body, and
think they are magnificent.

The MX is lovely if you want something compact and light though still
solidly built, but it doesn't have MLU so may not suit you.  There is a
fudge for mirror pre-release if you want to try it.  Does have a much
quieter shutter than the LX (silk versus titanium must make a difference,
the LX has a real 'twang' to it).

The MZ-S is a joy to handle, compared to most AF cameras I've ever used, but
is definitely nicer with the battery grip than without.  No gimmicks that
you don't need, everything that you do need is easy to access - only gripes
are minor: it can be a little too easy to switch metering modes by accident,
and that changing the functions/set-up - like whether you want to set the
delayed release to work as a self-timer of a mirror pre-fire, for example -
is not always intuitive, but then you seldom need to change these things.

Hope all that helps - feel free to post asking any more specific questions
and I'll reply if I know the answers.  Be interesting to hear how what
choices you make, and how you feel about them once you've used them for a
while.

Peter