Well, for your "application" 8mm will do. But you get better quality with bigger film size, depending on the reproduction techniques used.
But you are kidding us. Right? 16mm film is an older format than 8mm, Beta, VHS, and DVD. Why buy something that is relying on antique technology? ("Oh, the damn projector bulb burned out", as my father would say. And he's almost 80!) Do they still make movie projector parts?
I don't understand, unless you have the films converted to DVD, and keep the originals in someplace fireproof, weatherproof, etc.
James
BTW. I believe 32mm and larger (IMAX) is used for auditoriums.