[rstolz]

look into the headers closely, I know the OBX unit requires a midpipe as well, so if you need emissions testing, you'll be switching out the headers every time you have to test.

You won't get a whole lot of benefit from headers alone, you need the exhaust to be optimized as well, or all you've done is move the choke point, instead of minimizing it.

Honestly I'd start with the exhaust, then do the headers. Versaspeed.com is a solid first stop. I've got a couple of the DC pieces, and have been pretty happy so far, both the exhaust and the sway bar perform as advertised. The Silencer offered by Versaspeed for teh DC exhaust is a nice adder for when you need to drive with the wife, and she like her car rides quiet.

 

[rstolz]

you want a catback system, not an axle-back. Axleback is basically just a fancy muffler and a polished tip. not a whole lot of benefit there.

Do a little research and discover for yourself why installing headers and free flowing exhaust helps/hinders performance. It shouldn't take more than a couple hours reading articles or browsing forums to get the gist. Once you understand what these things do, you'll know at a glance if the parts are worth the cost.