a k&n filter is a good start.
Second would be to buy a good exhuast. headers and a new exhuast should give u a little noticable boost in hp. I don't know if a louder exhuast is legal down there though..
another easy way to possibly boost ur engine performace is to get a mod chip put into your ecu (computer) that'll make it run to higher revs and run your engine a little faster. That kinda mod is probably legal too.
i don't know anything about vtec controllers though or anything on making those better. Gonna have to get info from someone else on that. GL though.