The reverse decal/stencil is the way to go. Find a graphic designer friend and ask a favour. Wouldn't take too long in Illustrator.

Actually thinking about it, as there is a (for want of a better word) 'dish' on the rim edge it would be pretty hard getting a piece of vinyl to fit perfectly.

I think the vinyl letters would work fine and wouldn't peel off. They use this stuff on cars etc too.

Good luck. I plan to do this also......when I get time.