Honestly I wouldn't be able to justify spending 700 bones or more on a header unless it was being put on a motor that would be able to take advantage of it. A stock internals B18C1 is not such a motor.
For now a DC JDM 4-1 would be a pretty good idea. Just remember that you get no benefit from the 2.5" collector unless you redo the whole exhaust system to 2.5". That means replacing the cat with a 2.5" high flow one, and having custom 2.5" exhaust pipes bent back to a muffler (preferably with a 2.5" inlet).
I would rather spend the coin on a complete 2.5" system than the super-spiffy headers out there like Hytech, etc.