You can also go to Ebay and type in Cougar Headers for a search. That will return a few sellers with the Weapon R stainless steel 4 cylinder headers. Pick the lowest price that INCLUDES shipping, make sure the seller has good feedback, and you should be fine. The link that Hector provided to ZXtuner.com or whatever it was is a great source too.
DISCLAIMER:
Bid at your own risk as I do not assume any responsibility for action or inaction by anybody other than myself.