Well, at my shop, we only install magnaflow cats. because they work great, and last a long time.
Since you are in CAL. you will be going to smog tests (Test Only is most likely).
Those tiny cats probably won't get you thru the test. We see it all the time. If the car does make it, we call them 'one pass cats' because it likely will not pass next time.
Check out magnaflow online.
http://www.magnaflow.com/