I wanted to build two large manifolds for my OWB so I could run several zones from it in the house. Piecing it together of black iron fittings would run me over $300 in steel. Then I found Earth Lee LTD in NY (thanks to someone on Hearth.com). Lee Brooks (female btw) welds together headers of sch 40 steel or stainless steel. Her standard headers are 1", 1-1/4", or 1-1/2" main trunks with 3/4" or 1" tees. She also makes custom headers of all sizes and shapes. I just got a quote from her on two 1-1/4" headers with 4 3/4" tees for $80 plus $12 shipping. She uses American steel and these are welded together in NY. I haven't found a better product or deal elsewhere. I will be ordering shortly.
Here is her website:
http://www.earthlee.com/I had to contact her directly since she usually sells only to wholesalers, but there was not one in my area.
Here is an example of her work: