Well the new 2008 has the butterfly welded directly to the headers. So no matter what exhaust you put on, your not going to get any type of performance difference. So based on that, there is really no need getting an exhaust which will cost you alot of money.
Recommend Exhaust:
Jardine
Exhaust you can get but not needed:
M4
Hindle
I have a taylormade exhaust on my 1k and a Jardine on my 600.