This is such a clean and classic look, if you’re willing to look at a ring guard or double wedding bands, the symmetry would probably look amazing! Something like this Blue Nile band or similar could be nice on one or both sides.
I can’t quite tell but it looks like the milgrain is white gold...if it is, you could probably have a two-toned band set made to fit next to the ring perfectly and emphasize the setting! This ring guard - sorry for the Amazon link - would be fun if you wanted higher impact and the two-tone look.