Upgrading rings

When my husband and I got married we couldn’t afford to get super nice rings. I didn’t care, and still don’t, I love my ring! However, my husband really wants to upgrade both of ours. We will save our old rings away as a keepsake. Considering they’re lower quality rings it would probably be the best idea to preserve them.

One thing I dislike about my current ring is actually having to wear the separate wedding band. I’ve seen different styles of rings that people buy for anniversaries that are just a single ring. Would it be weird to upgrade to one ring? I really like the look eternity rings. I’m not sure if they’re meant to be an accent ring or if they can be worn on their own🤔

I’m also allergic to gold so I’m limited to silver metals. My current ring is sterling silver and is really scuffed up. Is there another metal I could try that would hold up a little better?

Any advice or opinions on this?