AEM is a company and they make the EMS, engine management system. It 's a full stand alone ECU and may be a little excessive for a bolt on car that hasn't had the engine or head worked on. Now if you plan on going FI down the road, it probably would be a smart investment.

 

I don't think im going to do forced induction and if i do it won't be for a longggg time.

 

Look into the Greddy Emanage ultimate with a plug and play boomslang/frog harness. Before that though if you are staying NA I would have at least header, testpipe, exhaust, and intake.

I can tell you the order I modded my car and I am happy with the results so far:
Catback
Intake
Testpipe
Springs
Header

Now the funny thing is, I am about to change catbacks (going a little quieter) and have to get the header installed. My next mod will be coilovers to replace the springs. So if I were to do it over it would be:

Catback
Testpipe
Intake
Coilovers
Header

I am not planning on staying NA, so I am not getting gears. If I go turbo, the intake and header have to be removed and sold, so I lost money there. If I go Supercharger, I only have to resell the intake.

Catback, testpipe, and coilovers are good no matter what your goals.