Go with the Helios pro mate, most retailers will have a deal on the price. The pro 6 seems to have a good coverage 4ft x 4ft @ 5ft high. I bought 3 of them for a 8ft x 4ft tent. I rang 3 independent led suppliers in 3 different areas of the country asking which was the best and they all said the Helios range was the top light out. They all sell other models of led lights ie evaded, photon pro, area 51 etc but all recommended the new Helios pro.
I am only a week in at the moment but everything looks a1 so far especially the heat issue, I don't have 1 now and my electric bill is cut in half. The pro 6 is equivalent to 600 hps, if I had 3 hps running, my plants would be cooking in 36-40 c heat, running with the 3 leds the temp is 25 -27 c . Might need to add a heater in the winter to get temps up a bit.