Super noob orchid mountin questions.

[DiggenEm]

Let me start this off by saying hello to everyone.

Ok Im a vivarium builder and i learned about this site from Vivarium Forums. Im currently building a rock wall paludarium and Ive seen builds with orchids mounted on cork, tree fern and other organic materials. My question is can and how to grow orchids on a rock wall and which ones are best suited for this application? I used quikrete mortar for the rock wall and here's a pic for a better idea of what I'm working with....

Any advice will be greatly appreciated.