any exhaust is going to help u. along with the k&n it will see a hugh difference in power.
the MOST IMPORTANT thing about these mods though and getting the most pwr out of them is JETTING!!!!! u will need to rejet.
i have the carbon fiber silencer and ss headpipe from GYT-R. love it!!! fit and finsh is great, nice sound, good gains.
and run the k&n with no lid, works great