Making a sleeper car, tips?

OK, I'm short of money so I'm buying my grandma's 96 Nissan Sentra GXE. Not a very sporty car but I thought it would be a funny car to make a sleeper out of. I'm going to buy a performance cold air intake, race clutch system and headers but don't know anything else to buy to make it faster. I was wondering if there are cheaper part swaps that could make the car faster, I would like to spend less than $1,500 after I buy the other parts. Also, since sleepers look just like run-of-the-mill cars, would it give it away if I bought some new rims? I want to do some body work, re-paint it white and buy black 15" rims.