I do not know of any one making a s.s. visor or stone guard for these trucks, depending what kind of s.s. they use, it could be too expensive. The cost of s.s. over metal or the plastic/fiber glass they use is enough for people not to produce it for fear of not selling them.
Your best bet is to make them yourself if possible.
The problem with s.s., they can get flash rust on the surface if not treated with a clear coat, the rust will not oxidize s.s. like metal, but it will be on the surface and look like it is rusting.