Check out www.speedwaymotors.com They've got some header choices in both cast iron and tubular for the two different type of Stovebolt engines.

Cast iron is going to be more trouble-free and a lot quieter. Tubular is just plain noisier. It's not a bad sound, but they do make more noise. For that many cubic inches, I'd probably err toward a small cfm 4 barrel carb.