DWRAT-
Sweat- looks like a Harris. Our guys sold one of those with twin 300 HP. Kick ass pontoon for about $85,000.
Only used Yamaha I could fine was in Fenton Michigan. Go to Skipperbuds.com and hit "used" top of page. Then go to far right to "modify search". Punch in jet boats as category and search.
Now you should also look for Scarabs as they have single 250hp in the 19 ft and twin 200 or 250hp in the 21-23 footers. Bad ass boats. If you want Scarab I may be able to help. I can hook you up with the dealer owner in Mesa who has a few. Email me direct at
bfitzgerald@skipperbuds.com