Before jumping in and spending a lot of money on a new camera and lens, you should try someting on the less-expensive side. There are literally hundreds of kind of fixed-lens rangefinder cameras, and some are stellar performers. .
Along those lines, you couldn't go too far wrong with a Konica--A Konica III or Auto S2 can be had very cheap. They're fixed lens, but the Konica Hexanon is awesome.