Take a close look at their specs. If 200W and 500W is their actual wattage, they should work just fine. When most LED companies say "500W" what they mean is "500W equivalent" which is a BS claim and the actual draw is probably 50-75W. I'm very skeptical of lights that are that cheap supposedly being that powerful.
Yes, I just found the SQ500, it is really 120W. It should work fine for a single plant in a 2x2 space. Perhaps you need 2 of them? Check out the Mars Hydro TSW1000 or TSW2000. They are a little more but they are much better lights and I guarantee if you buy these Lumeris you'll end up buying new lights after your first grow.