I'm fairly new to this site. However, I have discovered some wall hangers that I really like. They are made by Crawford Duramount and are available at Lowes and Amazon and elsewhere. They can be attached directly to a surface with screws.
I saw those too, but did you notice they have that offset designed into them so they'll fit into their brand of slatboard? You mount them on a flat surface and you'll have that gap underneath.
