I have a friend who's looking at getting into digital in a "big" way. He's looking at a Mamiya 645 (which shoots 6x4.5 cm images on medium format film - when using film) paired with a high resolution back. The Phase One P25 back he's looking at does 22mp images. The P45 which is available as well, will shoot 39mp images - comparable to shooting with 4x5inch film. Another back he's looking at is the ZD back from Mamiya which also does 22mp.
ZD Back
645 AFD II Camera
P25 Back
