It's not only the FSU cameras that were tweaked with shims under the lens mounting - my Canon P has a brass shim there as well. The matching of individual lenses to bodies is only applicable to the early FED and Zorki models; by the time the FED-2 came along, everything was nominally of uniform spec. Those FSU lenses should work on your Voigtländer; the fact that they don't tells me something is out of spec, either on the lenses or your FED-2 or both.
The Canon lenses are generally excellent. I have a 35/2.8 and a 50/1.5, along with a Leitz 90/4 and a Nikkor 135/3.5. The Canon 35 is very nice and quite compact (mine are the early chromed brass models); the 50 is really something special, but then I'm a sucker for Sonnars. The 50/1.8 has a very good reputation as well - being a double Gauss lens, it is quite sharp across the frame, and produces a fairly modern look.