CAI brand cai, perhaps a cat-back, ported throttle body. That's about it for the engine until more comes out (possible TB spacer).
Far higher on my list should be sub-frame inserts and goodies to tighten up the suspension. Later maybe move to lower it slightly/coil-overs/sway bars. Wheels and tires.
For me, I'd want to get as much mileage out of my dollars as possible, and at around $400 for the CAI that adds 15+ rwhp, that's a gimme. Ported throttle body may/may not add much peak, but should make it more responsive. That's less than $200 after core charge.