Hey Reeves,
Have you checked out the recent Car Craft? They document on building your own headers. Some of the ins and outs, how to lay them out, welding the flange etc.
They did some wild ones for a Gasser Fairmont with a stack injected 4.6 mod motor. They werent professionally tig welded either. Just a "regular" mig.
I don't know about your fab skills but hey threes so much help out there nowadays that its almost a "do you want to" and "do i have any time at all" issue more than some freaky zen deal on building your own headers. Oh yah and you do need a good amount of patience !!
After redoing my Mustang II headers with some bends from Jc Whitney,a few cut off wheels, a saws all, my mapp gas torch, and my inner shield welder (yep not even a true mig, lots of flap wheel grinding!) and 6 weeks of weekends I had them finished and they fit like a glove. Well sort of. I still made a few minor dents here and there in the foot well etc. But the satisfaction of doing it myself is almost indescribable!
Dont get me wrong, I had no preconceived notions of doing this from the get go. I was mislead by another V8 pinto guy (not from here) out on the internet who said his Cyclone/blackjack mustang II headers fit perfectly. When i got them they actually came somewhat close. If you wanted the headers to sit on the 71s cable steering shaft that is! SO i ended up staring at them for a couple of hours like they were going to fix themselves. Then my buddy came over and said " why dont you just cut these tubes out and re-rout them? Course it sounded easier than it ended up being but i said "Well i guess i have no choice" and then started to cut and never looked back.
Just some food for thought!
Good luck!