Thanks!
I set the cube up on a tray table and clamp the lights either to the side of the table or onto the top of ratchet clamps (which are clamped to the table), depending on the particular angle of lighting I want. I use 100 watt daylight bulbs. GE Reveal bulbs are good, but there are others out there. Just make sure that they are daylight, not soft white.
This is a ratchet clamp.