Ok so in doing some "shopping around" It seems that there a number of systems which would interest me.
I see the appeal of the Mamiya AFD system, but I can also see the appeal of the older 645 Pro / Pro TL sytems as well, not to mention the cheaper lenses and more numerous options for lenses.
In abandoning the thought of future digital purposes the appeal of the Pentax 67 still remains, though I wouldn't be able to afford the P67II.
I've considered an RZ67 again but I've had one before and while I absolutely loved it, I never got comfortable with using that camera off a tripod. I would like something that I can walk around with.
So let's just say for argument's sake, if I go with 645 let's assume it'll either be the Mamiya Pro / TL or the AFD, I could get more for my money with the Pro TL, but have less digital options in the future.
Or if I go with the P67 I'll have no digital options (outside of scanning, which is fine) and it will be more of a secondary camera. I do love the idea of shooting 6x7 negs again though....
It's amazing how difficult of a decision it is, I've tried quite a few systems out already in the past, and there wasn't one that I flat out DIDN'T like.
If I had to guess I'd say I probably wouldn't be doing A LOT of studio work with whichever camera I get. I have a full lighting system that I use with my DSLRs and I may dabble with doing studio lights again, but this would more often than not be an available light, hand-held setup, or locked on a tripod for landscapes.