Will be getting 30, 70, and 120 macro from Leica and round out with something in 45-55mm and probably a Mamiya 645 200 2.8apo
First of all, I'm envious
Definitely get the M645 200/2.8 APO. Also, the 24mm ULD fisheye is an optical treat. I use both of these.
The 50/4 shift is said to be very good, but only from about f/8 down.
If you want something faster and sharper at wider stops, there have been 6 different M645 45/2.8 and 55/2.8 lenses (C, S, and N for each focal length). Of the three I've tried (45 C, 45 S, 55 N) the 45 S seems to be the best at or close to wide open, and like anything else, it gets better stopped down. I haven't shot a lot with it yet, but from what I've seen, I like its bokeh too.