For a first ski,If you're looking at a couch, I'd look at a Yamaha VX110. It's not the fastest on the market but it's probably the most efficient. Not to mention the lack of maintenance. Plus a used one can be picked up relatively cheap. Just don't buy a rental. But that's another plus, they are ,at least around here, the most used by rentals. That should tell you something about how good they are.
IMO you should go rent and see what you want.
Rent here: http://www.sunshinewatersports.com/ for a seadoo gti. I've personally rented from this guy and he delivers and is the best deal or at least was two years ago.
Then there are some rentals by the beaches and st augustine that are more expensive but have the Yammy's that I was talking about.