v6 mods..

You'd be pleased with a 3.73 posi trac if you got those. 4.10's are little high for my preference only because I drive a 5-spd. If you have an automatic 4.10's would probably be alright.

If you don't have an intake though, after you put the flows on there you can deepen your exhaust some with an intake. I just upgraded my intake to the K&N FIPK kit. Its friggin great, I really think you'd be impressed with it.

With $1000-1500 you'd be able to get both these mods and have some money left over. After that its up to you, you could get a chip to calibrate your speedometer but then again i would wait until you have a more extensive mod setup before i would go the route of chipping your car. Pulleys are fun, x or h pipes are cool, headers; DON'T waste your money, better tires help, or do some suspension work on your car. Its really all up to you, have fun with it.