New to the world of pwc's. Looking to get a used ski. Something to break me in. I would like to here some feedback, specs, advice, suggestions, offer price, etc. on a few models. 1. '98 Yamaha GP1200. 2. '97 Polaris 900. 3. '96 sea doo XP. What kind of question are important to ask the seller about the ski? Any info would be greatly appreciated.