It is a lot easier and cheaper to improve handling than increase horsepower (won't kill your warrenty either). STi all the way!
Sorry you're wrong. It is more than a matter of springs, etc.
Power is easy. Simple dyno tuning on the Evo and it gained 30hp. It gained another 15 with a catback exhaust. With under $1000 in mods the US Evo has already ran 12.5x @ 107.xx 1/4's.