What kind of fondue?
I love cheese and chocolate fondues, but I'm a little icked out by meat cooked in hot oil or water fondue.
Assuming cheese and chocolate, I would think two or three fondue pots would be plenty, with different recipes in each. Do the cheese, then take a break and do the chocolate an hour or so later.
I wouldn't try to do this seated, either. Set up stations with fondue and dippers, and hand out forks and little plates, so people can dip and move on.
I think it would be a blast! You can always augment the menu with other heavy hors d'oeuvres like meatballs in a crock pot, crudite, etc.