Beautiful work Kelly.
Considering the recent improvements in the ceramic coatings available, I seriously doubt the need and desirability of building headers in stainless?
I had mine coated inside and outside and the coater has flow bench numbers that show the headers flowing a lot better coated inside.
I have seen several stainless sets recently and they turn all sorts of colors in usage. Cosmetic stainless, 303, 304 always had the reputation of splitting from the heat.
I already know it is very difficult to bend without kinks and ripples and it isn't that simple to weld.
Something to think about?