There are no offshore performance boat rentals in the Southern California area that I know of. I think you've be hard pressed to find an offshore boat to rent anywhere in the states period. Too much liability and wear and tear.
Catalina is an awesome island. I always get the European feel and a throw back to simpler times when I'm on Catalina.
I'm sure if you wanted to go for a ride (possibly rent a boat with the owner for a day) that could be arranged. You may want to post this question on the Southern California Offshore Powerboat Elite site ( www.scopeinfo.com ). They are based out of this area (long beach, Newport, Huntington beach, etc).
When are you planning a trip and how long?