I've had a similar setup for many years but built from pvc pipe. It has four shelves that accommodate 4 trays of plants per shelf, with two shop-lights per shelf. Used coated wire shelving units to set the trays on.
As other's have done, I hung the lights from chains to adjust their height, and never had any problems with breaking the bulbs. I haven't noticed much difference in growth rates between all cool-white, and mixed cool and warm-white bulbs.
