Congrats on the car. First mods i would do intake, throttle body, catback exhaust, and gears. If ya just doin one at a time id go ahead and get gears, makes the biggest difference.
-04 Mustang GT-Intercooled Kenne bell 2.1L supercharged @10psi, bolt ons, 3:73 gears, big brake upgrade, some suspension, 315's rear.
-08 Corvette Z06-B&B exhaust, K&N filter.
-12 Tacoma Prerunner