Thanks & I love your avatar, one of my favorite corals.
The rock on the back I purchased at MACNA also. It's called SEAZEN which is hand made by a lady who actually signs each piece. There were numerous rocks in multiple shapes to fit any tank. I was specifically looking for a flat back rock for this cube to give me room in front. I really like it. They have a site if you want to look around, let me know and I'll get it up here.