stormcase.com - get the "diced foam" one(s) and fit them yourself.

If you are looking for a fitted case for the camera like the old
cameras cases, they don't exist. While seemingly sounding like a good
idea they destroyed the ergonomics of the camera and developed the
"never ready case" reputation (they were called ever ready cases by the
manufacturers). Calumet sells something called a lens wrap which is
essentially a padded fleese cloth with velcro you can wrap around the
camera. They have worked for my 4x5 lenses , but I don't know if they
make one big enough for a camera and the 18-200.

Tom

I use a Pelican 1450 case for my D200 w/18-200 lens. The foam insert allows
you to custom fit the camera to the case, and the case itself is very
durable and waterproof.