Yeah, I feel the same way, like I'm throwing good money after bad. Still, if I replace the headers I'll probably have to replace the downpipe all the way to the cat (I am not even sure I have one), and that will cost me a lot of $. Same if I get the original manifolds.
I don't think the IAP headers are designed to go to a cat, but I imagine I could have cats fit in. Performatek has nice ones for about $250. They also sell CSC headers, which are very tempting, but just too much money for me at the moment.
Please let me know if you can find the copper gasket. I think if I can order the one from remflex, it might solve my problem. Certainly worth the $45 they charge.