I also think that you should handle the cameras on your list if possible, and I have no idea how to make that work. The camera that I love isn’t going to be the camera that you love.
I’m very fond of my Bronica S2A. I’ve had it less than a month and have put fewer than 20 rolls of film through it, so I can’t vouch for its durability. If I just went from the internet reviews I’d be terrified of it, but so far the Bronica has been a strong performer.
A perfect example of why it’s great to try these things in person if we can; I had nothing but admiration for my S2a. Extremely well made, durable and the Nikkor lenses were fantastic. Sadly, I never really got along with it because of it’s heavy weight and enormously loud mirror. Great camera, but not great for me.
So you want 6x6, light, cheap? Go with a folder, e.g. the Zeiss-Ikon Super Ikonta 532/16.
It does not have a TTL-viewfinder, but as I said: cheap, light, MF and has premium optics available. I picked one up for 80€ in perfect condition (exception: long times are sticky) and regularly use it.
I love MF folders but I didn’t recommend them to the OP simply because they’re mechanically fussy. Frames get bent, bellows leak, etc... Folders are the oldest of the MF stock available and, as such, are the hardest to find in good working order. I happen to love them but I don’t think they really meet the OP’s criteria. Not as closely as the models he already listed, anyway.
- Pentacon Six TL (CLA'd)
I thought of this, too, but “CLA’d” is definitely the most important thing here. Unless purchased from a known, reliable source former communist block cameras can be nothing but headaches. Once they’re thoroughly worked over they can be pretty reliable cameras but the more modern Japanese cameras the OP has listed really are likely to be less trouble in the long run.
Overall, I think the list in the first post is pretty spot-on.