best bang for buck is gears...

but I'd say get the vafc after at least after you get an exhaust, and if you can or you plan to wait until after a header...then do the vafc and you really only need to do it once. You wont gain that much from it though...regardless of when you do it, it will probably be around 10hp maybe 13-14after you are almost done if you are lucky and have an aggressive tune, and its a cold day, and...

 

That's an opinion of some people.

 

Useless???If there's a bad connection between the seat and the steering,YES.!!!