Some options we were considering

Instead of real marble get a marble look porcelain tile. They are available in matte or glossy.

Thank you lisedv. do you suggest matte or glossy? is it ok to to glossy floors with glossy tile?

I would do a matte tile on the floor. Another option would be a slate look gray porcelain. I have that in my primary bath and I love it. It's not as busy as a marble look, but of course different people like different things.

I would go for matte simply because it's not as slippery as glossy for a bathroom.

And, I agree with kandrewspa that a stone look porcelain tile could also be a nice option.