exhaust enhancement

I have a 1994 eagle vision esi, 3.3 liter engine with approximatly 150,000 miles. The car is in decent shape, no dings etc. and I'm fixing it up for my son to drive in a couple of years, I want a decent show car but not spend thousands of dollars to do it. I want to know how to enhance the exhast system for more horsepower and also so that it has that deep throaty purr or growl when running.

thanks
jason