i went with the lumatech 250w hps which ill be using soon,its great coz u can turn it down in power from the ballast and turn it up for flower saving electricity.
I have a 150 on one plant, for two it should work as well but any more and you're going to want to get more light
What's the dimensions of your grow area? You could definitely grow two plants under a 150w hps no doubt, but it's the size of your canopy area that determines the amount of light you need. I would say you could light up maybe 2 square feet of area with that lamp
dont have exact dimensions but gona be either in a small closet or under the basement which is a pretty big room by itself.
You should get a couple of ounces with that light. LST may be worth doing to help fill out your canopy