Mamiya 6 or 7 are great RF types of cameras.  You can always play around
with a Holga for like $30, or look into LOTS of good used equipment.  I
bought a Mamiya RZ67 II system, but that isn't the cheapest.  The Mamiya
645e system can be had for $700 new.  The Pentax 645 system is nice as
well, and the Pentax 67 system is a great alternative to the mamiya 7.  
Its more of an SLR type than a RF type but it's nice.  The thing would
be to start at the size of negative you want.  6x4.5, 6x6, 6x7, or 6x9.  
All of them are considered medium format.  This first choice will cut
down your choices in cameras.  For example, unless you get the Hassy H1
system at around $5K, you must go 6x6 for a Hassy...If you want 6x7 in a
RF style camerta, the Mamiya 7 is the way to go.  If 645 slr style, the
Mamiya 645, Pentax 645, Contax 645 are all available.  If you want the
option at a later date, then the Mamiya RZ can take 645, 6x6, and 6x7
backs.  6x9 is a bigger negative but there are some issues with film
flatness on some cameras.  

JR

Other than the Pentax 67, you'll find the MF SLRs _quite_ different beasts
to work with than 35mm and digital SLRs. And even the Pentax is large enough
that you may find it weird. If you want to try an MF SLR, I'd recommend
buying, not renting, on the grounds that it'll take time to get used to an
MF SLR.

For renting, I'd think the Mamiya 7 would make sense, since it should be
similar to the Bessa. The 80mm lens is a tad wider than a 50mm lens (it's
more like a 42mm lens), but it's a sharp lens.

One problem with MF rangefinders, though, is that there aren't a lot of
options that work well for portraits: lenses don't focus close enough
(Mamiya 7), or don't exist at all. Also, close ups are difficult. For
portraits and closeups, MF SLRs are, of course, wonderful.

One nasty problem with MF is getting your images digitized. MF scanners are
expensive. But even 645 with the Nikon 9000 will knock your socks off
relative to 35mm or the 10D, even at A4, if you are at all fussy about
detail.

David J. Littleboy
Tokyo, Japan

WARNING!!! looking at projected medium format slides may be hazardous to
your tolerance of lesser quality images from 35mm and digital formats! ;-)

renting is a good idea since ergonomics are usually more important to
most users than minor differences between lens quality etc., see list of
rental sources by state/phone at http://medfmt.8k.com/mf/rental.html

see http://medfmt.8k.com/mf/index.html and mf/cameras.html for camera
links and related buying articles (at top of mf/index.html)

see Danny Gonzalez's pro's hands-on camera reviews and pros/cons notes
at http://medfmt.8k.com/mf/gindex.html 

see mf/features.html for a chart of what camera types best match sundry
types of shooting situations (portraits..)....

see mf/system.html for systems oriented approach to camera system buys

see mf/available.html for lenses available by format and cost/brand (B&H)

see mf/value.html for best buys on MF gear and mf/budget.html for budget
MF options under $1,000 US$

see http://medfmt.8k.com/bronslideprojp.html for MF slide projector
options - there are lots of older used MF slide projectors for 645 and 6x6
slides which are available at often very low cost; 6x7cm and larger
options are more $$ or older/bulkier in budget range ;-)

if you are looking at current cameras, the B&H catalog for pro
photographers which covers MF and LF gear is a great resource (may be free
if you sound like a likely buyer ;-), call or email B&H etc.); lists
cameras, lenses, accessories and all that ;-)

used gear prices are now at historic lows in real dollar terms for many MF
SLRs etc.; you can probably try out a basic camera kit, and if you don't
like it, sell it on ebay with little loss in $$ (versus weeks of renting
costs anyway ;-)

keep in mind that you may end up with multiple MF kits over time, many of
us do - a TLR is handy for some types of situations, an SLR for closeups
or telephotos and so on, RF for fast or dim light work, mini-view MF for
architecture, and so on. MF lets you justify buying all these toys because
each is a bit different or useful in creating particular kinds of images
;-)

hope this helps

bobm