I've got a bench rig that's been running for 3 weeks.
Just put it on top of the anti-static bag it came with, with some thin styrofoam padding underneath it, then set all that on top of a cardboard box at least an inch high. The box it came in will work perfectly.
Elevating it will save you the trouble of removing the backplates from the PCI/AGP cards which would otherwise hit the desk and not install fully.