Come to think of it, If I were vegging in a 1.5 ft high space, I would stay away from CFL entirely and go with a T5 system using 2 ft bulbs. I would buy a cheap 4 bulb 2ft T5 setup and dismantle it, disposing of the case and using just the bulbs, ballast, and connectors (errr.. the bulb holder thingies whose name escapes me right now). I would then line the roof of the cabinet with mylar, and mount the bulbs to the top of the cabinet alternating sides, such that the first and third bulbs are butted against the cabinet's left side and the second and fourth bulbs are butted against the right side... or versa visa. This would result in the lowest profile lighting setup you could possibly put together and therefore waste as little vertical space as possible..... and besides, it would be fun to build