Each pot is about 9" in diameter. The rez is about 22". I think you could squeeze everything in your 5x8 space, but I don't know how much walking around room you will have. As for the lights, I think 2 600W lamps would be best. You have an oblong space and two lights will give you greater coverage. By the way, I have a 1 saquare meter grow tent and the max number of pots I can fit in there is 8. It would be 9, but the controller bucket is in there too.