Have you held a Mamiya TLR? I know by saying this I'll encourage people who climbed Mt. Everest with a C330 in their waist pack to chime in, but face it, they are big. And no matter how far out he bellows go, parallax is an issue with any TLR inside of a meter.

Interchangeable lenses- nice! Size- well, your call. At least it is very simple here- large size, interchangeable lenses, or small(er) size with fixed lens. For me, a fixed lens works best, so I give that up and get a camera I can carry in one hand for hours on end.

Don't choose based on a meter. Too many excellent TLRs with no meters or broken meters.

Condition might be more important than model. I'd take an aligned Rolleicord III over an abused Rolleiflex MX-EVS any day.

Anything of the Yashica level or up will do you well. Look around, but don't spend forever looking.