Very cool looking... It might be difficult to mount corals on the sides, though. Encrusting corals would look good and grow over it while still leaving the holes open, and I can see Acropora growing well there if your tank is established. What it really needs is a group of barnacle blennies, they'd love that sort of thing. A midas blenny, citron goby, or longnose hawkfish would also use it as a home. Very nice design, if I knew anything about ceramics I'd try to make something like that.
You can grow any coral on a vertical surface, don't worry ; ) looks like it has enough holes for light to penetrate into the interior as well. I would line that entire thing with zoas! You can do sps and lps encrusters as well, but many may fight with eachother once they start to touch...