Doncoryon,
First get your car running top notch. Since you don't know the history of the car you just purchased, I'd get a full tuneup (plugs, wires, cap, rotor, fuel/air filters, pcv, coolant flush, oil/tranny fluid change, etc. Then I'd get a shifter, gears (3.73s), offroad H-pipe, 2.5"...