I made the mistake of over tightening the bolts when my first set of gaskets blew out, so ever since I've battled leaks in between the two center ports (due to the flange being warped). I tried a good set of gaskets, then double gaskets (blew them out in a month), but I had the best luck with Percy's Seal4good aluminum gaskets. They still leaked a little in the same places, but since they're blowout proof it never got any worse. I just had my headers ceramic coated so when I put them back on I'm going to double up on the gaskets, reusing the old set (they're reuse able).
http://www.summitracing.com/parts/php-66037/overview/make/chrysler