wow the prices for all these aftermarket big name headers are pretty high... for $400 you can get the APN header, the stock 2.25" downpipe, 2.25-2 1/2" adaptor, 2 1/2" in/out hi flow cat, 2 1/2 center in/offset out flow master 40 series all shipped to your door.
apn: 145
downpipe: 75
adaptor: 2
hi flow cat: 60
muffler: 75
total is about $375 and a majority of this stuff you can get from your local auto parts store (IE: cat, down pipe, adaptor, muffler) the only thing to order is the APN header and it flows pretty nice. Just get an exhaust wrap for it.