CARB legality is not that big of an issue, folks. At least, not right now. h:

I'd go with your choice of the following: AEM, Greddy, Apexi, DC Sports, etc.
The certification process is arbitrary and expensive.
So to justify the investment, the brands that have CARB EO numbers (and are thus legal) are widely advertised.

It's not like the issue of CARB legality is some big secret.

Beware though, that some exhaust systems - like the Apexi N1 - may be emissions legal, but will not comply with the state's 95 decibel limit for exhaust noise.

I went with a custom system fabricated by my local shop. Flows beautifully, great exhaust note, not too loud. Passed with flying colors.

And a final note: Don't run a straight pipe and expect to pass our smog checks. It simply won't happen.