It would be awesome to have a glass topped cigar humidor modified to house the computer in the bottom and actually hold cigars in the top. Some humidors have drawer(s) large enough to allow a disc tray to be inserted for the DVD drive. I believe a 50 cigar humidor would be large enough to allow the mobo in the bottom. The glass top will provide the illusion that the computer is just a humidor. Also, you will see in one of the attached pics there is a humidity gauge that could be replaced with a temp gauge that displays the CPU or internal temp. I also believe the humidor should be on small feet (say an inch) to allow air vents to be installed in the bottom for ventilation.
I've included a couple of different humidors to help get the ideas flowing.