as far as exhaust goes, id spend the 300 on the non-emission pacesetter longtubes. hit up autozone or something for their ceramic coat paint. coat your headers inside as best you can, and do the outside. and if your oven is big enough (mine is barely) use a clothes hanger to hold the header upright. keep it on preheat, and leave it at about 450 for an hour. you now have your coated long tubes for ~$304.92 before tax.

if anyone questions this method, i did this to my intake piping, as it sat very close to the exhaust manifold, and i saw an average drop of 6-10 degrees. all the variables were practically identical, nothing other than the coating could have made a temp change such as that.