Yosh or Akrapovic would be my first choice, since both are among the elite in build quality, both aren't obnoxious loud, and both seem to be the leaders in performance - backed by racing results worldwide...
Got my Akropovic on order
"Keep yer feet on the pegs and your right hand cranked."
Got my Akropovic on order
"Keep yer feet on the pegs and your right hand cranked."