Stainless sparks as well as non-stainless, at least in my testing. The determining factor is the hardness. Hacksaw blades work well. Glass works very well, harder than most steels, but you'd better be careful.

High hardness, and a sharp edge are what you need. That's why when I pair a knife up with a fire steel, I test it, and prefer the knives whose spine has not been rounded.