We had a Yamaha GP1200, and that thing was awsome. I'm 255lbs, and it had no problem pulling me around skiing or getting me up out of the water. The bigger the craft, the smoother the ride. We had a smaller, one person Yamaha, and it was a rough ride, but I could get it up to 54mph (WOT on Sunday mornings on a glass-like lake). The fastest I ever took the 1200 was up to 59mph, but I never had it at full throttle. It could handle myself, plus 2 passengers, and it was like there was no one else on it.
I think the most maintenance we did was my dad replaced the battery on the smaller waverunner. Never had any problems starting, and I had LOTS of fun, meaning I was thrown off on multiple occasions. Bottom line, bigger is better. The biggest one you can afford will allow the most fun for everyone.
Also, not sure where you're located, but if it's near AL, and you want a used beginner's kneeboard, and some other stuff, I'm sure my parents wouldn't mind me getting it out of the basement.