I got a plastic wall mountable planter from Lowes and planted it with small cattleya hybrids, a dendrobium, and a bunch of rhipsalis! Holes were drilled for better drainage, and I used an orchid mix for the substrate. I rigged it so it leans on shelf brackets and is held in place by a hook and wire so I can easily take it indoors on cold nights. Here's a link for more info on it.
This looks terrific. I've been interested in the vertical garden idea for some time, and considering how to use orchids in this concept. Please do keep us up to date on how your garden does!