-FRPP (not Mac, not BBK, not anything else) Ceramic Shorties
-Offroad H (upr stainless one is good)
-Your choice of catback. I recommend the Dynomax Ultra Flow
The stock headers are so bad its not even funny, they are 1.5" primaries but some moron at Ford decided to put kinks in them to make it easier to install the header bolts so they are more like 1 or 1.25" primaries... Keep your stock mid-pipe hung up on a wall or in a shed and swap it back in for emissions testing if you have it. Swap it back in a few days prior to burn any crud out of the cats.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.