I know I struggled with this when having mine installed. There are so many variables. I found this article online that sort of raps down some of the things to consider. You could also look at houzz and sort by bathroom wall mounted faucet. Luckily, mine worked out great. You can look at mine by searching at the bottom of this page for Treetop (I posted pics with that name).

"Julius Ballanco, president of JB Engineering and Code Consulting in Munster, Ind., says since wall-mounted faucets take more abuse, contractors should choose a sturdy one. "I will pay extra money for a solid-brass connection," he says.

Bartlett cautions remodelers to make sure they can find parts for whatever type of faucet they choose.

Height and depth

Bartlett also advises contractors to "measure, measure, measure" when installing these faucets. "Have your sink available to take measurements from to make sure you have the right height," the plumber says.

He says that although there's no standard for wall-mounted faucet heights, contractors must leave an air gap between the top of the sink and the bottom of the faucet. "Don't let the faucet go inside the sink -- that's a code violation. You need 1 inch of airspace between the top of the sink's flood level and the bottom of the faucet," he says. On the other hand, if the faucet is too high, he cautions, water will splash out of the sink.

Tim Mullally, president of KWC Faucets, in Norcross, Ga., says the company's Vesuno faucet extends 6, 9, or 12 inches from the wall. "The height of the faucet will depend on whether you're using it with a vessel bowl, a bar sink, or an under-mount sink," he says. Since the faucet is mounted on the wall, it also requires a longer reach to operate. Mullally says that if the primary user of the bathroom is a child or is short, make sure they can reach the handles."