Most all hardware stores and building supply stores carry stainless
steel screws.

MAYBE they carry a small selection of screws and these are just for the
boating crowd. There just isn't a wide selection of SS fasteners at BIG
BOX or "local" hardware stores.

I've never seen stainless nails but they're probably out
there.

The only place I have seen them is on the TV shows. Somehow, the local
places never got the word.

Word is that you can also use hot dipped galvanized hardware,
but not electro-galvanized. They even make brass coated screws that are
supposed to be compatable with the copper content, but I found that
they break very easily.

Well, if the copper in the wood is destructive to the fastener, how could
plating the fastener with a copper alloy help the situation?