catalytic converter

Want to get a catalytic converter on my 92 prelude si i was wondering if anybody has suggestions on brands.......i was thinking about a universal one off ebay.....basically what it boils down to is i want my car to be louder but still be legal. thanks for the help

was thinking about this http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2480908300&category=33629

also do i need an air tube or not?

random technology has one o th e best cats u can get. i gained porlly 5-10 whp from it, but that may have also been my ixygen sensor was bad?!
it has a great sound. also chek out carsound