I know people say alot of crap about the Hobie 16, but I would be willing to bet that there are more people who learned to sail on one than any other type of cat, and for a quick set up, and just a blast to take out the H16 is gonna be close to your best bet.
I can't see any 14 foot cat being fun with three people on it, I have taken three on my Hobie 14 and could barely keep it upright. Even 3 on my Nacra 5.2 which is 17 feet is crowded.
Also H16 are easy to find and can take a beating.