My local Farm Fleet type store keeps stainless wire in 2 lb. rolls. My welder won't take those little spools so this spring I ended up welding a stainless motor plate w/regular mig wire. So far it's held up fine.
Told a buddy about it after the fact. He said he's in the same boat so he keeps a little roll of stainless around and just pulls what he needs off the spool, strings it out and the wire feeder'll pull it through. Duh for me.