Tris; I'm stuck behind a screen editing and don't have a beach or a pretty lady at my disposal so you win
Yes but it isn't cost effective.
Mamiya ZD back is a lot of money for 22MP - you achieve higher resolution by using film (or just buy buying a D800...)
Digital backs from Phase One etc are available but they typically require expensive adaptors to make them compatible. Then there is the question of aspect ratio...
The camera itself is superb in its fully mechanical format - Mamiya
RZ bodies are preferable for digital as opposed to the above RB and can be acquired relatively cheaply.
Heavyp can probably confirm - I believe he's been playing with them a lot longer than I have.