Board (Empire Shockwave is recommended)
Bolt (Lurker or Boss)
Barrel (Lurker and Deadly winds are good ways to go, maybe the rumored Empire freak system)
Lurker poppet when it comes out
Depending on your barrel it will be $700 (Eigen Barrel) or $800 (Deadlywinds with Boremaster)
Barrels do nothing...
I'm pretty sure a dealywind fibur barrel would be lighter, quieter, and give you better bore/paintball control than a stock Axe barrel.