if money is an issue, and i'm sure it is for most of us on camaros.net, why not just use your stock exhaust manifolds until you save up enough money to pick up a good set of headers. That'll give you plenty of time to figure out what you need for your setup (accessories, clearance, coatings). Also, this is the reason i'm not getting headers for my 327 with a 282s cam, when you eventually install headers, you will be able to experience first hand, how much more performace you are gaining. And maybe after, you will have a true opinion about why or why not to install headers with experience to back it up.
1968 Coupe, 327ci basketcase project
1986 Chevy Stepside, 305ci/300hp