well, My 300 is 30" deep and I run the Evolution G1 120 watt LED units, from Reefkoi. I have a mixed reef and am able to keep chalices and Acans on the sand, as well as some lower light SPS. I get about 90 par on the sand.
I am using these geting great result mixed reef. sps I have been getting great growth and i believe to be a really good price when u look at what u are getting in the lights