my budget is just about that, i am going with gears and nitrous. a shifter and subraframes also.

 

if you can do the work yourself you'll save a ton of money. I would do intake and exhaust, along with the midpipe. Once thats done I would do gears, shifter etc. S/C i dunno if you'll find one for 800 bucks but that'd be nice haha. I found a UPR o/r x pipe for 80 bucks on craigslist, anything you can find slightly used will save some bucks. a lot of guys buy stangs and mod it out then realize they cant make the payments anymore so they end up changing it back to stock, so sometimes you can find great parts used for cheap. goodluck moding man i love my 04

 

s/c--super charger...

I would do a intake, throttle body, plenum, underdrives, handheld tuner, x pipe ( no cats) if allowed and some flowmasters. I got all that for under 1K. the flows are about $65 a piece. I got 2 flowmasters and a custom x pipe made for $220...with the listed parts you will feel a differance in your car. Gears are a good choice but the install is on the pricey side if you cant do them yourself. Since you have a auto like I do I would go with a set of 3.73s.