Originally Posted by traveler_101
I don't know what "ZI" is - Zeiss Ikon from before the war or what?
Sorry. ZI = Zeiss Ikon. Latest version, not pre-war, though those are also very nice as well.
They all work, even the little Voigtlander Bessa cameras (again, recent versions) so buy what you want and enjoy it. Unless you are thinking that a camera is some kind of investment, you pick what you can afford.
Besides, it all comes down to the film and the lens. The rest is just a box with a lens mount so buy the box you can afford.