Sounds like a nice set up. Anubias and moss on the wall will look great. You could try out java fern and Bolbitus as well. The planted rock wall, a couple of rosette plants and some low growing stuff sounds like a nice scape. If the rocks in the sand matched the wall it would look more cohesive than the white rocks I think.
I didn't think the white rocks would look all that natural, but I thought it would feel somewhat surreal and kinda dream-like or something. I'm not sure if I'll do the rocks though since that would get pricey. I've got some windelov java ferns that haven't really done much since I got them back in June. Not sure where I'd put them though. Aren't they supposed to stay above the substrate as well?