Catalytic Converter for LT1 Mids.??

I have a 94 z28 a4 cai, and fan switch, flowmaster catback. I want to get some mac mids, but ima need a new cat also. I have two questions:

1. Best Catalytic Converter

2. Best CA Smog legal cat

The ones on Ebay are cheap and work fine. I am unsure if they will pass emissions there.