Film bodies that take digital backs

First of all, it is not my intention to raise from the dead one of those "comparison" or "film sizes" threads.

I need a medium format film SLR for my portrait (and maybe landscape) work and I'm thinking of the possibility of renting digital backs occasionally and maybe even buying one some time in the distant future. What should be the right way to go about this? Some people say that one should not get a film camera hoping to go digital in the future, since such bodies are usually negligible in cost compared to the digital backs and are even offered free along with the back sometimes.

Should I pre-empt and get a body that can fit a digital back, or should I just get whatever I want now and worry about the digital back in the future? Also, in terms of real world standards (no pixel peeping or any of those "techie" theoretical tests) is it safe to say that if I choose a 645AFD over a RZ67 I will not be losing much? I have shot all the medium format sizes except 645 so I don't have an idea of its size.

Medium format with added digital back can be fairly cumbersome...so getting a more recent body that was designed to accept digital will facilitate the use of the digital back.

Also, being able to mount a digital back without a special adapter plate is beneficial.

The Hasselblad V and H line is compatible with many if not most digi backs. If you have way too much money the Rollei Hy6 is fully compatible with sinar digi backs. The H-line can often be found for less money than other similar aged Hassy bodies.

I think it all comes down whether you want AF and auto exposure. If yes, then better buy a Hasselblad H or Phase One/Mamiya. If not, buy the RZ67 or a Hasselblad 555ELD.

This is off topic for APUG, but a good topic for our sister site, DPUG.