When I had my wheels re-done I got stainless Buchanan's. I can't remember what vendor I bought them from. It might have been DCC. They're nice for sure. Tons of threads about them on here. Can't say about other spokes, but I know there are some other decent ones out there. I think most would consider stainless Buchanan's tops for quality, etc. They definitely cost more.
I don't see any $50 stainless spokes from Z1?