Well, to be honest I have:
hmf pipe
ceramic coated headers
hard rock air box
white bros. air filter
170 main jet
To put it best, the pipe is the first thing to do, the largest power and performance increase.
2nd the air-box mod is good, and frankly the best thing I can say about the airbox mod and filter is that the top-end smooths out.
before with the pipe and with out the airbox the top end broke up, jetting was perfect, but it was getting a vacuum back up after a long long straight away run.
now with the pipe and the airbox it has perfect power band and there are no points on the powerband where there are hick-ups.
I can say this, the difference is well worth it.
call hardrock, the prices are amazing.
for trailtech bars, 3 jets, a midrange needle, filter and airbox mod it was only like 200 shipped. plus i got filter oil and other odds and ends.
hope this helps.