You've discovered a versatile and affordable system. Good luck with it!

Lenses of more than about 120 mm adapt pretty easily to the Bronica system. The registration distance is 101.6mm, if I remember correctly, but the rear portion of the lens can protrude into the mirror box, thanks to the falling-mirror design (this is why the Nikkor 40mm/4.0 is such an outstanding lens), so with shorter lenses you need to experiment a bit. Adaptations I've done include a 24 cm Voigtlander Heliar for portraits, and with a little help from S.K. Grimes a 500/5.5 Schneider Tele-Xenar, and with a little help from Frank Marshman I have a Canon FD-Bronica bayonet adapter for macro use.

The Tele-Xenar was a real coup. I think I paid around $300 for the lens in excellent condition, but in barrel (originally for Speed Graphic), and around $275 for a custom S.K. Grimes adapter tube to use it with the Komura focusing Helical II, which takes 300mm, 400mm, and 500mm heads, and which I already had with the 300mm/5.0. Imagine how much you would have to pay for a 500mm lens, perhaps even the very same 500/5.5. Tele-Xenar, for Hassy or Rollei, and such projects become very attractive.