I would highly recommend Sunshine Watersports. I reserved the jet skis online. Arrived at the site about 10 minutes early to complete the paperwork. The person working the jet skis was great and very helpful. This was my second time on a jet ski, so I didn't open it up too much (only got up to 41 mph), but my partner knew what she was doing. She said she was able to get to 70 mph.
Only thing I would caution you on is on parking. The rental area is next to Gilbert's Resort. There is a small beach and a couple of great bars, one with live music. The beach and party folks park along the road leading up to the area. That can be over 1/2 mile away. There is a small parking lot near the jet ski rental. A couple of guys help with the traffic by the bar, so if you go, ask where to park and they will fit you in.