Take a look over at http://www.turbomustangs.com I am assuming you are doing a ford. Also look up the user B&G Customs he is in Hamilton Ohio and does all the fabricating of headers and related tubing.
A quite a few people just use the f-cam and one guy over there "Brent" is well over a 1000rwhp with it. Otherwise I vote for http://www.camshaftinnovations.com as well "Jay Allen"