This will get moved to tech pretty quick.
Before that, I'll answer what i can
Cheap and easy route to more power:
GT40 heads, aluminum if possible Classifieds.
Cobra or GT40 intake. Classifieds.
E-303 Cam Ford Racing will have those, as well as 47482 other companies.
Gears. 4.10's. Don't fear the gear. Motive makes decent ones.
Exhaust, get a good midpipe and some headers. Lots of company's make them. For a cat back, flowmasters are your budget's best friend.
As well, lower the damn car. You'll enjoy that both visually and in how the car handles. Eibach and H&R make good kits.
Get some cheap subframe connectors. They're cheap and will make you feel like you're no longer driving a shopping cart.
/end lesson