I started with a Mamiya C330 and over 30+ years built it up to a system with 4 lenses and 2 bodies.
I then got into a Mamiya 645 system, and built it up to a system with two bodies and several lenses.
I then added a Mamiya RB67 with one lens, and after a fair bit of acquiring and trading (at one time 3 bodies) now have a single body and a good selection of lenses.
So basically, I am saying: "Be careful what you wish for ".
All three systems have now been pared down somewhat (just a single body for each), and I have streamlined the lens choice. For example, my C330 is now accompanied by just two lenses, and the whole package (with waist-level finder) fits nicely in a very small camera bag - like one designed for a 35mm SLR with a single 28mm-85mm kit lens.
The Mamiya TLRs are where I would start (again) if I was making your decision.