Developing old rollfilm

I'd be interested in any information on developing and printing old rollfilms. Especially what equipment I would need. I know I need a developing tank capable of taking the larger sized films, do I need a projector for printing? Any advice cheerfully accepted.

As you say, anything bigger than 120/620 is going to need a tank to fit, which will likely be a stumbling block. After that, the bigger negs lens themselves readily to contact printing, an enlarger for anything bigger than 6x9 will be "professional" prices unless you get lucky second hand.