This is all about personal opinion so you'll get tons of different replies I'm sure. First off what are your plans for the car? na, turbo, n2o? If turbo then a higher diameter catback is best thermal is tight, same with greddy imo. HKS makes nice setups too but some tend to deteriorate after a few years. (this is just what I've heard) The best prices i've found are at www.asylumms.com or there are a few guys on the board who might be able to hook you up better then they.