i gotta a borla header, highflow (supposedly magnaflow cat), flowmaster 50 series (original not the delta flow), and runs through 2 1/2 pipes. Sounds pretty bad ass under throttle, and its a nice bassy rumble at speed on the highway.
DEFINATELY get the flowmaster heat shield. It attaches with giant hose clamps, and maybe while you have the old muffler off , try putting on a DEI reflective heat shield on the floor. The flowmaster heat shield is like 15 bucks, and a DEI reflective heat mat is like $11-13 i think. Worth the insurance. My original muffler rusted my floor so it needs all the help it can get.
get a small piece my local hot rod shop has little ones the size of a muffler heres a link for ya
http://designengineering.com/products.asp?m=sp&pid=27