Apex'i world sport for more torque and a not-so-loud deep growl (loud at high rpms) or n1 for more highend and a little louder sound.

n1 is a great exhaust, but the WS isnt too bad either. it's what i have, but honestly would have liked the N1.....i just got mine for dirt cheap.

either exhaust is good though i have pics of mine if you would like to see.