longshanks r6

Hi There, This is my first time doing this,so here goes my name is Karl i live in Rotherham,South Yorkshire.I've just taken delivery of my brand new 08'R6 and what a beauty she is,got it in red,black and white and in the near future having it painted up in the santander haga replica paint scheme. I'm after getting an aftermarket exhuast fitted and was wondering if anyone out there had any advice on which one would be the best choice to go for regarding performance and sound. Regards Karl.