Hello Rebecca, i would try checking out Century Hardware's -4 (Satin Brass) finish. i think it would look great with that awesome light fixture!

Glamour · More Info

Modern Geo · More Info

I wouldn't be trying to match lighting fixtures to cabinet hardware. Mix your metals.

Delta faucet has a finish called champagne bronze which online looks like your light fixture even though Delta doesn't call it brass. Delta has a finish called polished brass but I don't think that's what you are looking for.

https://www.deltafaucet.com/bathroom/sink

https://www.us.kohler.com/us/browse/bathroom-bathroom-faucets-faucet-families/_/N-2dkxZ1z113x0Z1z113y9Z1z113xgZ1z0uy9iZ2e84 has several shades that would go as well and also https://www.rohlhome.com/bath/bath-faucet.