Heres an idea of what some TQ/HP will cost at Zippers, I have no experience working on the engine and do not plan on experimenting with it either...looking at doing this on my ride soon once I ride it for a bit longer...
Oh yeah...ad another 800 on top of it for the Thundermax and auto tuner (I plan on buying this seperate and installing myself).

 

Cams and a set of 2-1 pipes with a dyno tune and you'll be golden.