downpipe/cat question

My downpipe needs replacing. I figure why not put a 3 or 2.5 inch pipe on now. I see pipes that say for 1g all the time but does it matter mine has a 13g turbo or??? And another thing is this is my everyday driver, I need it to pass inspection when the time comes(in NJ no less)so I will need a cat and will a Hi Performance Cat pass inspection? Any idea's anyone? Im open to hear them, thanks in advance for any help.

Ok well no one replied yet but anyways I found a short DP on RR engineering's site and you can buy the high flow cat seperate. This will cost me just about 400 just in parts though(230 and 150 plus S&H). Anyone no of any where else so look besides e bay and trader????????????????????

there is nothing wrong with the meagan downpipes sold on ebay. i know alot of people who have bought the $110 meagan 3in mandrell downpipe. if you want a short downpipe just have a mufflershop cut the cat-eliminator peice off and weld the flange in the appreate place. shouldn't cost more then $50

thanks ill look into that