http://www.tccoa.com/articles/misc/index.html#
That is the BIGGEST gain to be gotten off the SC, and most of it is really easy to do, and a lot of it doesnt cost anything.
Second, you're saying the car already has a performance exhaust and 10% pulley?
A raised top might help but right now there's a big debate over whether or not a raised top even does anything. If you've already done those there isn't a whole lot left you can do, except go with a double-core intercooler or convert to front mount intercooling with a larger unit. Everything else after that performance wise looks pretty expensive or the gains to be had are minimal at best.
WEIGHT REDUCTION, WEIGHT REDUCTION, WEIGHT REDUCTION.
That sound deadening that's everywhere feels like it's heavy so I would suggest removing it, finding an aluminum spare to replace your stock one, or just don't carry a spare, remove your back seats, pull up the carpet and pull out the sound deadening and then replace the carpet, do the same to the door, holesaw the front and rear bumpers, etc, etc.
Oh, and if it isn't already, get a 5-speed.