Just purchased APC Symmetra RM 6 kva. Rack size is 10U and it weighs 390 lbs. I'm looknig for a rack enclosure for it and having trouble find a rack enclosure smaller than 24U that can handle the weight of the unit. I've thought about purchasing a wall mount enclosesure that has an option for rubber feet or casters but they only support about half the weight. Any suggestions?