I have a Bessa R which I have only had for a few weeks. I also have a 35mm Color Skopar lens. So now that I am in love with the Voigtlander. What would be some reasons to upgrade to better Bessa? What's the main differences in the Bessa line and could I use my screw mount Color Skopar on any of them.
Cosmo
Have you checked out www.cameraquest.com? they have a wealth of information on all the Bessa cameras. You can definitely use your color skopar on the other bessa's for the M-mount ones you would just need a thread-mount to M-mount adapter which you can getfrom cameraquest.
You can use the screw mount lenses on the others, just need an adapter. The other Bessas are heavier and feel more solid, as well as allowing faster changing of lenses. I use an R2 and an R. I bought the R2 because I had been given a bayonet mount lens, not because of any deficiency in the R.
Good advice above. Why don't you just use the Bessa R for a while? It's a good camera (I have one), and performs all the necessary functions for the rangefinder experience.
The nice thing about a rangefinder is that even if it has interchangeable lenses, keeping just one lens on the camera for the day is a great way to learn composition.