One last piece of advise, 3W Leds, 1W Leds, 160W Units, 75W units...etc...
These numbers are only the total wattage of maximum diode output would be...if they were powered at the max.
One very important point to consider, almost every LED manufacturer conveniently leaves out exactly how much wattage the diodes are TRUELY being driven at. A 3W diode can run with 1.5W and yet they will still boast 3W Crees. The reason? The cost of keeping the unit cool when driven at higher wattages.
So keep in mind that a 120W unit could very well be running only 80W or 90W simply because they can market their lamps at lower prices because of cheaper components to run at lower temperatures.