I have a few old folders, so I guess I can give some advice.
The best of what I have, and also the easiest to use is the Moskva 2. 6x9 negs, coupled rangefinder, compact when folded and not too expensive. What is not to love about this camera.
I also have an Ensign Commando, which is alsoa coupled rangefinder toting beasty, but is significantly heavier and a bit harder to use. The focusing mechanism on the Commando is of the film plain focusing and is rather heavy/stiff to use due to the strong spring behind the film plate.
Of the non rangefinder folders I have, the Ensigns, Kodaks, Kershaw, Franka and Coronet are easy to use, with some of them being fixed focus and with minimal shutter speed and apurture options.
Don't count out some of the non folding 120 cameras out there. Some of the TLR's are great cameras and can be bought for very little. Yashica and Lubitel are 2 names that come to mind. I personally have a Yashica A TLR and I love it. Nice 6x6 negs and the lens is quite sharp.
Good luck with your research on this subject and let us know what you decide. Any questions, just PM me and I will be glad to help.
Heath