IIRC, Tilapia are legal south of the Tehachapi Mountains but not north of them. Santa Ana River Lakes (Aquaculturist in Anaheim) sells Tilapia hornorum, Tilapia mossambica and Tilapia zilli. I don't know anything about Tilapia (ask Rex). Tilapia are a favorite fish to catch in the Salton Sea, 3+ pounders have been caught there. Heck in the Palo Verde Canal a lady caught a record Tilapia at 3 pounds 8 ounces.
Link to Tilapia Record. I'll bet that put up quite the fight.
I believe Peacock Bass are illegal in California, none of the "Registered Aquaculturists" sell them and that is a good clue.
You could do a Hybrid Stiped Bass/Tilapia pond in So Cal. That would be a blast to fish. (Santa Ana River Lakes also sells Hybrid Stiped Bass, I've never purchased from them because my place is in Northern CA so I cannot offer any personal testomy regarding them).
