The torque is the biggest factor for you.....I would look at some dyno numbers for people who have done mods that make more torque, not always peak power. How about a new camshaft....that will help the powerband if it's within the budget. Don't always think an AUTO is a bad thing, it's much easier to heat your tires in a burnout and if you have ever run the 1/4 or have been at the track then you know that automatics can be quite helpful. If you are going to stay with an automatic, then look into a really good torque converter coupled with a better final drive gear. There are a ot of ways to free up speed out of the stock drivetrain rather than juice the car on forced induction and risk blowing something in the bottom end. Sure, most cars can handle a few PSI, but in the long run that should be the topping on a built motor.