Having remodeled several homes, my advice to you would be to visit one of the larger tile stores such as Arizona Tile:
https://www.arizonatile.com
Visit when you have a few hours to work with one of their consultants. I have found them to have a pretty unique selection, and the folks I have worked with there are thoughtful and considerate when assembling a solution for me. You just might be blown away by how great you can make a bathroom look when you step back for a moment and consider several options. Bathrooms and kitchens sell homes, as important as the latter, is that women love their bathrooms. If you are married, it's probably a great idea to have your wife accompany you to Arizona Tile. It's just a fact of life that women have a different lens through which they view this (and other) types of choices. They tend to spend a lot more time in the bathroom, so they seek ambience, amongst other factors when making choices of this nature. It's really a force multiplier having your SO along with you when seeking ideas. It's an important decision as you're going to be looking at that bathroom for a long time.
You may pay a little more going this route, but you will certainly get the wow factor going, and it's actually a lot of fun when you take the time to consider several choices. You might, in your case, actually pay somewhat less, as incorporation of tile into your project while you are still using marble, may reduce costs. I also find a lot of inspiration looking at Houzz.com - their photographs are incredible, you can set up albums on their website and save the images of bathrooms you like. Good luck!