If you'll give up on the RF, there are viewfinder cameras that will do what you want. Alpa 12, for example. Nothing personal, but you can't afford one.

If you'll give up on the RF and focusing helical and can live with focusing on the ground glass, you can use a Century or 2x3 Crown Graphic to shoot 6x7 or 6x9 with a variety of lenses. 35/4.5 Apo Grandagon. 47 Super Angulon, f/5.6 or f/8. There are longer lenses too.

Look at your budget, look at what you want to accomplish, and consider relaxing your requirements.