I'm going to go against the grain and suggest to steer clear of the gears for now, especially if you have a manual. They unquestionably make the car feel faster in higher numerical gears because 2nd now feels like 1st, 3rd feels like 2nd, etc., but they actually don't make the car a whole lot quicker. You're talking a tenth or two actual improvement at the track, and that's depending on one big thing: traction in 1st gear. Because steeper gears REALLY start making it difficult to get traction in 1st gear, they often actually cause you to be slower if you don't have a good set of rubber to hook it up. While I love the 3.73s on my car, hooking it up on the street in 1st with street tires is quite difficult, whereas it used to be no problem with the stock 3.27s.
I'd also suggest holding off until you know the direction you're gonna go with the car. A mild bolt-on car would command a different set of gears than a supercharged car.
Other than that, I agree with the others' suggestions to do FLSFCs /
suspension first. That will always be beneficial regardless of what direction you take with the car. I'm partial to the
Eibach Pro-Kit springs, as they are a nice drop that still have a nice ride, and don't absolutely require castor/
camber plates (it's better to have them, but not necessary). And either Tokico HPs or the Eibach Pro shocks/struts are good bargain buys.
Exhaust is something else I'd do early on, as you can always enjoy that, and it is again beneficial regardless of what you do with the car.
Other than that, I wouldn't spend money on anything else unless you absolutely knew that you won't be supercharging it. Most of the other bolt-ons are not necessarily interchangeable from NA to supercharged, so you'd likely be wasting that money on bolt-ons. Not to mention, all the bolt-ons total (CAI, T/B, upper plenum, UDPs, etc.) are only worth a couple tenths in the 1/4 at best.