i was looking at that hanging one....looks like the one you want plus it would lok cool in a grow room...might want to look into how easy it is to get replacement lamps...if it is propeietary it may not be worth it. i dont think they are made to stay on for 12 or 24 hrs at a time so i would expext to go thru a few lamps. i do not know alot about HPS and MH as i have never used them myself so i cant tell you how many plants that will work for but i know if you look around on this crazy interwebnet thing you can find a way to calculate sq ft and determine lumens needed. that is the important part...also you will need to think about heat. i know it sais fan cooled but you will need more than that. good thing its OSHA compliant, wouldnt wana get busted by them:wtf: