My history with headers has been painful enough through the years such that this is probably one area I wouldn't skimp in an effort to save money. Leaky, ill fitting headers can drive you to throw wrenchs all over the place (ask me how I know...). That said, Dougs Headers & TTI are the two brands that get the most praise around here. I've used several sets of Hooker big block headers on my Roadrunner with mixed results, and have had no luck at all with Hedman (wouldn't clear starter). From what I've read here both Doug's & TTI route above all of the steering linkage and have the best fit & finish. If I decide to go the header route on my 73 small block Barracuda I'll use one of these two brands. Sorry, no experience whatsoever with the mufllers you mention. Good luck.
Later, Jim