PaulLin--Orange County is near LA, right? If so, then you are in the US MECCA of BJJ. It's very easy to find good BJJ. I'd avoid the Torrance Gracie academy because of the prices. Plus, I've heard Rorian's business practices are somewhat suspect. This is what I have heard mind you--I'm not speaking from experience.
Do not get hung up on learning from a Black Belt, although in your area, that shouldn't be an issue. The basics are the basics and can be learned from a decent blue belt. Purple belt instructors with their own school are not uncommon.
Next Generation Fight Academy teaches a good deal of No-gi submission grappling, heavily fight oriented, vice sport BJJ. It's run by Chris Brennan, well respected in the fight game, and he is in Irvine California.
Combative Fighting Systems has Ken Gabrielson as their instructor. He is a black belt under Reylson Gracie. They are in Westminster.
Torrance has a Caique school somewhere, I think, and also has Torrance Gracie and Torrance Machado I think.
John De La O teaches in Huntington Beach, I think.
Anyway--you have a TON of options out that way...
Side note: Wrestlers and BJJers don't attack the legs without setting it up...not the good ones anyway
"In the world of martial arts, respect is often a given. In the real world, it must be earned."
"A stupid man's report of what a clever man says is never accurate because he unconsciously translates what he hears into something he can understand. "--Bertrand Russell
"Liberals - Cosmopolitan critics, men who are the friends of every country save their own. "--Benjamin Disraeli
"A conservative government is an organised hypocrisy."--Benjamin Disraeli