^ personally i don't think yoshi is a reputable brand for making power for CBRs. Most guys on the 600rr forum, don't have much HP gain from yoshis. but look into akrapovic, leo vince, arrow.
$800 for a yoshi
slip-on? you have to be kidding me! thats the price of an akra slip-on for me! Or why not save up a bit more and get the full system? Make some power at least. The slip-on is only good for making noise.
this arrow looks dope
http://www.baysideperformance.ca/ind...oducts_id=5623 $700