K-Dog

Hi everyone I am new to the for I just picked up my first jet skies. I have been really enjoying them and would like to get a stand up ski. I have been looking at the older ones because of price. I am trying to decide between a heavily modded Kawasaki 550 a 1988 Kawasaki 650 and a 1991 Yamaha superjet 650. I am leaning more towards the 650's because of my size, I am 250 lbs.

Would like to get some input on witch is best for a beginner and will just last the longest. I would rather not have to do a lot of mods if possible.

Thanks