Well a cold air intake would be a start. Then headers would definately help it out alot. Just stay away from the Pacesetter ones, they're crap. If your having a hard time looking for performance parts, then just try to find some that are made for the 3.4L. Same block, just bored out. Otherwise they're identical. So if you can't find headers for your 2.8, then the 3.4 ones would fit just fine. Try checking out Full Throttle Performance, they have a huge selection of V6 performance parts that you can use. They say they're for the 3.4L, but as I said, if it's a bolt on then it should go on without a problem.
http://www.ftpp.net/V6Main.htm