Your local ACE Hardware will have 'em in stainless. Take an OEM with you & fit a nut to it to determine size & thread pitch.
Then pinch the threads between your thumb & forefinger and slowly and lightly touch it to a buffing wheel for about 15 seconds [with polishing compound] and she'll shine like chrome which will last quite some time.
Yes, I can be a cheap

You can use an old "borrowed" t-shirt, instead of spending all the bucks for a buffing wheel. Not to mention the electricity savings. Don't listen to that profligate with his extravagant spending!!!
ditto on Ace - I've been in several, now, and they seem to have the very best Hillman selections around. They STILL don't have the elusive 10mmX1.25 bolts for adding the Hitchdoc, but everything else I have looked for their, they've had.