Originally Posted by CBRich

As stated you can go with the Fast Intentions Long Tube Headers which will give you piping right back to the start of your exhaust. If you don't want to replace the headers at this time (looking toward turbo at some point) you can go with the Berk test pipes, ERZ resonated test pipes, or some of the high flow cats from those companies or others.

For maximum flow you want the test pipes but they could cause some undesirable sounds with your exhaust. In that case you could go with the high flow cats and just lose a few horsepower.