My earlier post was related only to Rolleis, since it seemed like that was what you really wanted. What I would actually purchase would be a Mamiya C-series camera. They are more versatile (7 focal lengths plus the benefits of bellows focusing), and the lenses are as excellent as any higher-end camera, at least to my eyes. The weight issue is not a big one IMO. It's true that if I only need a normal lens, I usually shoot my Rollei for the day, but for occasions in which I might want to use different lenses, the slightly greater weight of the Mamiya is well worth it to have that ability.
People also think that they are fiddly. I see what they mean; there are lots of switches and knobs and interlocks, and the f stops and shutter speeds must be set directly on the shutter, not with handy knobs like a Rollei. But IMO the fiddliness mostly relates to useful features, and does not detract from the camera in practical use. Some examples are: 1) lens lock/unlock knob (also activates flap inside the camera to cover the film when changing lenses), 2) single/multi exposure switch (actually just an interlock that prevents the shutter lever from being depressed more than once on the same frame; I always set it to "multi," even for normal shooting. If it is set to "single," you cannot press the shutter lever halfway, decide not to take your shot, and then press the shutter lever again without flipping the switch to "multi." After missing the right timing on a few shots by this interlock, I decided to always keep the thing on "multi.") 3) focal length setting for parallax indicator bar on "3" models, 4) manual shutter cocking on "2" models, 5) shutter speeds and apertures must be set on the shutter itself, like a large format camera.
One note on the Mamiyas is that I would consider a Paramender to be a necessary part of the camera if you plan on focusing on anything other than infinity or close to it. They can be around $100.