For portability at a reasonable price, a 50s folder with rangefinder is a good bet as quite a few came with excellent lenses. I can think of the likes of the Zeiss Ikon Super Ikonta or Ikonta M, Agilux Agifold, Agfa Super Isolette, Balda Super Baldax, Mamiya Six, Olympus Six, Adox Golf or the late model Voigtänder Bessa II with the 6x4.5 mask. This is far from an exhaustive list of good-to-use folders with capable lenses. If you like the sound of a folder, condition is paramount, check for light leaks in the bellows, skewed front panel and rangefinder misalignment, shutter operation and lens fungus or de-lamination before parting with cash. Prices for most of these are on a par or slightly less nowadays for equivalent condition Yashica-Mat or Minolta Autocord TLRs so you could try a folder or a TLR and if you don't like it, sell it on and trade on to another type. I used a Yashica-Mat EM for a while and liked the results (it had a surprisingly good lens) but found it a bit bulky to carry so sold it on. Most of the 70s and 80s era SLRs from Japanese and German manufacturers are vastly more adaptable machines but are on the bulky side and will require more of an investment in a system to take advantage of that adaptability so I would recommend a fixed lens camera so you can just try out MF first.