Okay so your budget is $5k.

You would want (as a good all-round platform):

-Revert back to stock BOV (better for you in the long run).
-Downpipe
-*edit* Fuel Pump
-Tune (Ecutek/Verso....use the search button for more info)
-Slotted rotors
-Better pads
-Beter brake fluid
-Stiffer springs
-Bigger swaybar/s

Then you'd have more grunt as you want (specifically, a lot more torque). As Kato said, no point upping the power and then relying on stock brakes + suspension to keep you away from trees/poles/old people.

If you aren't giggling like a school girl from those mods, save up some more $$$ get a VF34/P20 or a TD05/20G, set of injectors if required and a retune. Giggidy

My 2c.

Happy Modding.

__________________
65.3 short track (wet).

Getting better. Still somewhat retarded.

I am just a dad with a couple of kids who loves cars, but not like the mad love often displayed here. I drive my car/cars daily and do high mileage.
I went DBA 4000 slotted rotors, Bendix ultimate pads.
It stops as well as my new betty STi in daily driving situations, possibly better due to less pedal pressure required. In fact, as a daily the WRX stops better.
Do not thread crap (I know less fade yada yada) I am just saying about daily driving.
I went ecutek, with cold air intake, walbro fuel pump and 3"TBE.
It was a new car, seriously worth every cent of the roughly 5K all the basic mods cost.
It will put your car in stock STi territory for power/torque. Roughly. It will be noisy to drive though.
my 2 cents worth.