Do you have a stick or automatic ? Do you plan on staying n/a or do you plan on going boosted(nitrous, supercharger, or turbo) in the future ? This will help in determining what is best for your application.
If youre planning on staying n/a, then I would go with 4.10 or 4.30 gears. Some might say thats a bit much but then again all the top n/a times on this board have been achieved with no less than 4.10 gears. If youre going boosted, then Ide go with 3.73's. Not to say you cant go with 4.10's and boosted at the same time, but you'll probably need a taller tire to keep from running out of gear on the track. Go to
www.stangstore.com for the cheapest price on gears.
When switching gears, you will definately need some sticky tires. I recommend a spare set of wheels and drag slicks to throw on whenever you go to the track. If you dont want to switch tires, then a good set of DOT approved drag radials would be a good idea.
Pullies on average yield about 5-10rwhp gains with similar numbers in torque production. If you get any, I would go with Steeda as theirs tends to be the most popular and of best quality.
If you have an automatic, then you definately need a chip for the gear change. If you have a five speed, all you need is a speedcal to correct the speedo and Ide recommend getting a short throw shifter for the five speed as this will help with the swiftness of your shifts. The cheapest place I know to get the speedcal is
www.brothersperformance.com
Note: If you have an automatic, the best thing for you is to put all of your money twords a shift kit, torque converter, gears, and chip or dyno tune as this will yield the best results.