Well here's the problem. If you get a bunch of bolt on type header, exhaust stuff, it won't flow enough later on down the road for whatever big spiffy n/a build you make. The one thing that you won't exceed the flow capacity of later on is a good intake like an AEM CAI, so go ahead and get that. Also don't get an underdrive pulley.

Secondly, you're not going to increase low end power. This is a small displacement motor and the way you make more power is to get it to flow more air and to rev higher. If you get aftermarket cams what you're essentially doing is moving the power peak higher up in the rev band.

If you haven't set up the chassis fully, I'd concentrate on that and then worry about the motor. You're not going to break into the 13's (I'm assuming this is on street tires with a GSR) without building it up rather extensively. You'll need a helluva lot more than 2 grand to do so.