hi im looking to get a stand up jet ski but im unsure. i will be riding in a river mostly so the water isnt too rough but i will bring it out into the sound ocasionaly. my firiends will be riding 1300cc 3 seaters so i would like something that wouldnt be too far behind them. i see a lot of 650sx for sale localy and a few pjs what would you suggest for a beginner. i heard that the 650sx are kinda slow but you can make then fast with a new impeller exhaust carbs etc.