I'm the guy who thinks more about performance than look. Still i care about look.
From this list, please put them in order that you would buy them in order. I'm tight on money so for now i have to choose one of the options for now.
1) Greddy Ti Exhaust system
2) GF 210 springs, alignment kit and 3 yr alignment warranty (possibly shocks when stocks blow)
3) 18" wheels
4) extra set of 17" drift wheels
5) JP vizage type front lip
6) Hotchikis sway bar

EDIT: forgot to add a sway bar

 

Why don't you do the plenum spacer if your short on dough!! It's like $300 and ppl boast of gains upto 20hp. It's a seems like a nice DIY and a lot o bang for your buck! That's the next mod I can do/ afford lol

 

i've got MD plenum spacer, JWT popcharger and hr-y pipe.

 

I would say exhaust. Adds a little with the butt dyno and makes the car sound meaner. Springs are a dime a dozen around here. Every week someone is trying to sell them.

 

GF210 Springs, Shocks, Alignment kit + Alignment! Having the car corner with less roll > spare wheels or an exhaust :P

The Tanabe GF springs are real nice! Going to help my friend install his GF springs on his 08 STI today too.

 

If i only had to buy the springs then i'd definately go with that. But the alignment kit cost quite a bit. Since GF 210 is quite a big of drop, there's more chance of blowing the shocks that i later have to replace with.

 

So would you say hotchikis sway bar for less roll for cheaper way than drop?
The spare wheels are for drifting. Since i'm into drifting now, the spare wheels seem like must for me..but that won't improve performance.

 

Honestly I can't say for sure.

Since you like drifting, the cheapest way to get your car sliding more I guess would be to get just the hotchikis or any stiffer rear sway bar... Your G will oversteer much more with just a beefier rear sway bar. I don't know if Hotchikis sells the front and rear individually, but I know Tanabe does sell the sway bars separately. Eventually you'd have to get springs anyways.

What I would do is get the GF Springs first, then get the sway bars of your choice. If you decide to get the Hotchikis one, just slap on the rear sway bar first and try it out. You might like it, you might not... if not, simply install your front sway bar and see if you like it better. Just my two cents.