Replying to Standup Jetski

Looking to purchase a standup Jetski. I would like to find a superjet but can't find any in the price range I'm looking for. So I'm gonna most likely get a kawasaki. A few of my friends ride and say 650 as small as you want to go unless you will get tired of it. The thing is though I'm only 5'2 110 pounds so I'm wondering if a 440 or say 550 would be enough ski for me? Or should I just go with a 650 so I won't come bored and have to purchase one later. I'm new to the sport so what should I be looking for while purchasing? Any helpful advice you have I would appreciate, thanks! I'll be purchasing in the seattle area if that makes a difference.