vert bulbs? the fuck? you just hang the lights from the roof in a socket, no need to buy anything new. Make sure to have enough air conditioning to cool this because you probably wont be air coolint vert.
some bulb mfgs claim that hanging the bulb one way or the other is more efficient than the other, based on who makes the bulb. Some bulbs I believe can only be horiz, some vert, and the majority of hps bulbs can go either way. Is it an mh or hps bulb?