The plan is NOT to have sconces in there, but an over-mirror fixture! All suggestions gratefully accepted! I have absolutely no brain cells left.

Mari, we had a similar situation, but if the room is being used for grooming I would really recommend going with sconces even if you don't think you have the room. According to all the advice from the experts I googled, we didn't have room for sconces either. I really wanted sconces since everyone said they gave much better and more flattering light (and who are we kidding, we need all the help we can get). I got a big sheet of mirror and had the sconces mounted on the mirror. Here is a pic of our mirror. Our vanity is 22.5" wide. If this really isn't an option for you then I would get a framed mirror with dimensions slightly smaller than your vanity width. If you are getting something prefab youre probably going to be looking at 24"x36"

They have some cute 16 to 18 inch vanities online that give at least some storage. This is under $600 so a bit pricy http://www.bathvanityexperts.com/avanity-kent-vs18-cf-18-inch-coffee-transitional-single-bathroom-vanity.html?dfw_tracker=9185-3425&gclid=Cj0KEQjwofHHBRDS0Pnhpef89ucBEiQASEp6LIhlOKd-xRSAUHHngn6lTzsstfRtgdHCFzlvK2yiyGIaAs9N8P8HAQ

Ok, here we go. The bathroom is actually currently two bathrooms, separated by a pocket door original to our 1968 home. The first picture is of the "hall bath," which currently holds a vanity and a toilet, opposite one another and is so small you can't see the toilet until you have already closed the door behind you. On the other side of the pocket door is another toilet and the bathtub. Our plan is to put the vanity in the current location of the toilet in the first picture (furthest to the right.) So, the vanity, toilet, and tub/shower will all be along the same wall. Does that make sense? It is so tight with the wall and pocket door between the two spaces it's hard to get photos. Needless to say, it is pretty awful right now. So the wall on the left, between these two spaces, will be gone. There is about 36 inches from the far right wall to the edge of the toilet that is staying, thus the 32" vanity. We have 8' ceilings.