hmm. wheels+tires are expensive, even rotas.

i'd get a set of GC's and shocks with the same money. Should run you 600 -700 bucks.

as far as engine mods go, u might want to look into I/H/E cuz it's a good place to start. should run you around 800 if you go with an AEM CAI, DC 4-2-1 CC header, and a Apex'i N1/Worldsport.

If you want to make serious power or are thinking about going turbo one day, don't bother with the DC header. If you're gonna stay NA and mostly bolt-on, it's an affordable option.

If you want to get really serious about your headers, save up for a mugen or an SMSP, (mugen 800-900, SMSP costs 1200).

the more cost effective mod will be the suspension work, and that's what i'd recommend. though don't be cheap and just get the springs/coil-overs and run em on stock shocks

good luck