I guess there isn't much point to posting now, as the OP asked his question 2 years ago....
But about Rolleis:
The SL35-M is *not* Identical to the Voigtländer VSL 1. They are very similar and both derived from the Icarex, but the VSL 1 has much more metal in it and, notably, has a much better shutter speed dial (including the smoothness of the click stops).
The SL35-E (= Voigtländer VSL 3-E) was notorious for its electronic problems, but those were fixed in the later series cameras and in those sent back for repair.
While probably not the World's most reliable camera, one now working properly will probably keep working for a good while...
It is a very nice user.
I have 3, just in case!
The SL35 can be fairly reliable (if you find a working one), I just don't like it. The very expensive-because-sought-for-by-collectors SL35O could be a definite improvement and looks interesting, if you have money. I keep hoping to find one of those mythical Spotmatics with a Rollei mount.
Selling Zeiss lenses to *upgrade* to Canon EF is pure nonsense, unless you really want autofocus.
With one or two exceptions, the newer lenses will *not* bring you better quality. In most cases it will be a definite downgrade.
Another advantage of the Rolleiflex system is that the 35mm f/2.8 and the 85mm f/2.8 (both reputedly different schemes from the Contax equivalents) are excellent and tiny, making them my SLR lenses of choice for travelling/mountains.