I'll add my vote for the 645. I bought mine a few years ago and it was my first move to MF from 35mm. I was blown away by the detail and the lenses are wonderful. I got mine from KEH for a good price, (can't remember exactly how much - their prices seem to fluctuate with time. They had a lot of inventory at the time so I had good choice in lenses). Hand holding is not a problem for me. I'm not a big fan of auto focus, so don't mind the manual lenses at all.