A catback is a waste of money, unless you like to pay for sound. No HP to be gained. Just weld in your mufflers of choice. The stock mufflers dumped with an offroad mid pipe sound the best to me.
4.10's are going to give you a hard time at the track on street tires, unless you have experience slipping a clutch. Gears make a car fun to drive, but don't make it faster unless the proper tire/driver techniques are applied. Many times, they make the car slower at the track by inexperienced drivers with street tires spinning half way down the track.
If you want to learn how to drive your car at the track, I would not touch it. Spend the money at the track, then fix anything you break. After you get the hang of it, then mod it. In a stock 5 speed PI car, you should be running 14.0-14.2 @98-100mph if you DA is -1000 to 500ft. If the DA is higher, then the car might run in the 14.3 and up. 60ft' with track prep should be mid to high 1.9's.