OP, if you are looking for a car that will be faster than a WRX, or other performance car in a straight line, you will definitely need to look into a turbo kit. (Tom's kit would be easier than swapping in a complete ST drivetrain, although that has been done)I have tried to research on my own and found nothing so far, but i was wondering what my options would be as far as swapping my engine would be?
If you just want a car that is peppy and fun to drive around on twisty roads, there are inexpensive mods that can be done to the handling (rear sway bar, lowering springs, etc) that will really transform the driving dynamic of the car.
Considering you are in high school, you most likely do not have the funds to do a turbo kit right now. If you want to squeeze some more power out of your mk3 I would save up your pennies for Tom's tune, and do some supporting mods for it (exhaust, intake, etc). That will be a more cost effective way to spend money. Another very cheap but effective mod i the steeda or whiteline rear sway bar. Most consider it the best pound for pound mod to do. If you like how the RSB makes the car feel, try out their lowering springs.
These cars make a very good platform for spirited driving on a twisty road, and with a few mods and a decent driver, it will be just as quick as most cars.