Andrew Demko is the inventor of the Triad Lock, and his customs use it. I've had some contact with him, and he's pretty agreeable about weird stuff like this.
(TL's quoted passage was here)
Personally, I doubt that you will be able to find a company which mass-produces replacement blades for CS products in different steel flavors. I'm no expert, but it does not seem like a product that would be in great demand, and I'm pretty sure they would get their pants sued off! The shape of the blade tang is a part of the Triad mechanism, and that might be enough for Cold Steel to prosecute a successful lawsuit.
I'm curious about your thinking, too. I could see having blades that were satin, or stonewashed, or some other finish, for a more formal look or a more functional finish, but the only reason I can see for wanting different steel types is for very different applications. Maybe a blade made of S7 or something if you expect to be doing naughty things, and a blade of VG10 or ZDP for slicing....
Can you explain the thought process you went through?