Funny, I actually just got a Mamiya RB67 Pro-S a couple of weeks ago, basically the kind you're referring to with the bellows focusing. You can always look for a Mimiya 645 (6x4.5cm) which I believe focusing at the lens, although it has a focal plane shutter rather than a leaf shutter like the RB/RZ series has.
The Bronica style 6x6 TLR looks nice too. An advantage to those is that there's no mirror swing, you just hit the button and the shutter triggers. I will say, the RB67 is quite a heavy camera, especially compared to a modern DSLR with anything other than a super-zoom on it. The waist-level viewfinder is great, and unless you're doing real hurried street photography, accounting for the light fall-off and using the knob to focus is not a problem. Once I get a good neck strap and the adjustable grip, I might just try out some street photography with it, but until then I'll mostly just be on a tripod.