Bathroom Cabinets

The bathroom light is 12V. There are a great many 12V fixtures available (for RVs, boats, cars, etc.). There are also 12V light bulbs available that screw into ordinary 120V fixtures, which would permit you to use those if they are otherwise suitable. Mounting some 120V lights might take a wee little bit of ingenuity since they're designed to be used with an electrical box. (For 12V operation, the electrical box is not really necessary because the shock hazard is basically nonexistent.)

I thought the bathroom light was 12vdc,

Is this a wall cabinet you are looking for?
Places like Home Depot and Lowe's have a ton of sizes, styles, options, etc.
Also, light fixtures are generally not RV specific. You can find lots of choices at the same place.

Or, you can always have something custom made at any cabinet outfit.