My Bryston 3BSST sits at the bottom of a typical solid pine audio cabinet. I know, not ideal, but it seems to work fine. I'm sure an audiophile-approved support stand would be better, but I'm surprised that the sound is as good as it is with this typical family-room type of stereo furniture.
I had cut-outs put in the back for connections and airflow. The 3BSST gets just slightly warm and never really gets hot.