Dont buy that crappy Meizhi light. COB LED is where you want to be. You can dial in your spectrum, power utilization, and light angles. You can DIY (cobkits.com) or pay double or more and buy one. Typically in bloom, you have a cob light at least 12" away from canopy, and at least 18" in veg. Most seem to put them a little further. I'm in flower right now, 15" away.
Grab a measuring tape and find out how much grow space you actually have. Assuming you can raise your light 15" from the top, add the minimum distance to canopy and the rest is your grow space. Subtract the height of your pot, and that is the largest you can allow your plant to get. Half of that distance is the height your plant needs to be when flipped into flower to get the most bang for your buck.
Hope that helps,good luck and happy growing.