I'd try to find chrome lighting but I think mixing the nickel is fine. I would not choose gold.

I've never expected lights and faucets to match simply because one is electrical and the other is plumbing. I do expect all the lighting in the room to match, especially a small room like a bathroom. It is best to choose all your lighting from the same "collection" by the same supplier. Here is a link that shows what I mean. At least the vanity and sconce lights would match. There is a chandelier too although I do not care for it.

There are plenty of vanity lights with shades on Restoration Hardware in chrome in the bath lighting category. The Chandelier can be a champagne and an intentional ACCENT........stay away from nickel, it has a greenish cast that will appear a mismatch. The best bath lighting is a combination of recessed and sconces, if you can do that, and avoid the vanity lights above altogether. A three light is generally plenty as well, if its' your only option

https://www.restorationhardware.com/catalog/product/product.jsp?productId=prod5210039&categoryId=cat4980014

Definitely you should go with polished nickel for the look you hope to achieve. It is the most glamorous and you can get lights, hardware and faucets to match. Here's an example of a PN faucet that really shows the finish. To me it's the most classic and elegant. Gold can be interesting but it might be a fad - these are more timeless.

Thank you for your comments! Would a crystal chandelier work with either the chrome or polished nickel?

Absolutely yes for crystal chandelier!

RMI-Rebecca Mitchell Interiors, thank you so very much for your comments. I really appreciate your advice!

My pleasure - sounds like you're going to have a beautiful bathroom - post photos!