I use an IKEA wall shelf to lift my monitors off my desk. The thing has just enough clearance to have the Mini under it and an inch and a half clear above it for airflow, and was a pain to place at the right height at the time (concrete walls).
Maybe you could use something like the rail-and-cantilever shelving scheme you find in a lot of stores. That way, you only have to install it once and the height is easy to adjust thereafter.
