Xyphota

EDIT: Title was supposed to be "Stainless or Non-Stainless". Sorry for the confusion.

I can't seem to find the answer to this using the search function, so sorry if this is question has been asked before.

I'm building up a single speed frame with some Reynolds 631 and wanted to try silver soldering in the water bottle bosses. Should I get stainless or non-stainless bosses?

Additionally, at what wall thickness do people use those bottle boss reinforcement stars like the ones offered at BFS?

Thanks