It won't be quite as wide on 6x6 as on 6x7, since the 6x7 is a wider negative. If you crop the 6x6 to a rectangle, its about the same image area as 645 format, which is a lot smaller than 6x7. You'd probably want a 50 or 55mm on 6x6. The Rollei Wide offers this at an extreme price, or the Mamiya C330 series TLRs offer a 55mm, 65mm, 80mm, amd 135mm interchangeable lenses. That would be my choice, the lenses are cheap, very good, and you can own several lenses for one body! I did my graduation project for art school on a Mamiya C330f. Loved it, had to sell because of poverty in the years after I graduated
🙁 I still miss it, but I was later able to get a Hasselblad, which is nicer but more costly (the 50mm CF-FLE lens I have for my Hassy costs more used than a Mamiya C330f with 55, 65, and 80mm lenses combined!)
I shot these with my Mamiya:
Oh and the Mamiya focuses to a few inches!
Another ultra closeup. This is the door handle on an old car, the first closeup is the car's mirror!