You could mount just about any mini on there!
A friend if mine had a large piece of soapstone, about a foot wide x 6 inches deep x about 6 inches tall. It also had lots of little nooks and crannies and he mounted a bunch of different minis on it, making sure that they were all within the same cultural needs like lighting and temperature.
I'm looking forward to seeing what you do with it
With yours being taller rather than wide, maybe look for something that will cascade for the top portion?