You can buy a furniture vanity base and add any kind of marble, granite, quartz countertop.

Here is a link that might be useful: Vanity Flair sells cabinet bases in all sizes

Check out Silkroad Exclusive. I bought one from eBay, but there are other sellers, too. (It came with a vein cut travertine top, but I wanted my own stone, so I took it off.)

Restoration Hardware has numerous furniture style vanities with marble tops. Additionally, you can purchase the base without the top and have a top made out of your choice of material.

If you are a Costco member, they usually have some available on their website. We purchased one in store for our powder room that is a little larger than that with a marble top.