Oh yes a Hasselblad back would be great on the 6008AF if your work is not that focus critical. Its a heavier camera but reliable....and on that point remember that you could get a 6008 integral as a backup but its a pig to use. There won't be much support for your combination so you'll have to be brave.
You'll need a plate and probably a set of shims to get your focus right and a mask to go in the viewer, I'm sorry I can't remember if it goes on top or below but one of these ruins the focus

I did look at the Leaf and the camera is wonderful but the digital back is not. This way you can have a great camera (not quite as good as the Hy6) and a great digital back but you'll lose the integration and the lens correction (which you might not use anyway) of the H3D and of course your widest lens will be a 40mm as opposed to the Hasselblad 28. You might think this is too wide but I now use it all the time with its amazing corrections.
I should imagine you can pick up a CFII 39 at a good price and as long as you are brave and capable and willing to learn the foibles of a hybrid camera you should be fine for at least 3 years.
Back to my sick bed

Monty Rakusen