question

use the search button, but look in to the Lrd and factory 7 pipes they both are great also new v force3 reeds are great and a custom airbox or something. As for suspension theres a whole section devoted to it with a description and write up of most of the cheap shocks you can have, it pinned at the top of the suspension section.
 
For an exhaust, it really depends on where you ride. Some are better for midrange while others are better for topend. As far as suspension goes, works, yfz450 with some mods and elkas are all really good shocks