http://www.topledgrowlight.com/reflector-led-grow-light-96x3w.html#.VEF8gqxOmSw I was hoping to just buy one. Will it be sufficient for up to 3 plants?
No. That light will not put out enough light. Maybe for 1 plant. For comparison im using 3 300 watt led fixtures in a 3x3 tent. It seems to be doing well so far. So in total im using 900 watts of leds. The one you linked wasnt even 200 watts... so anyways go 400+ watts if you want to grow something worth the time and effort.
You can get a 400w hps/mh set up for the same money. You will also need some air flow, a fan to extract and one to circulate the air in the grow space. Spend an hour going through a good beginners guide http://www.growweedeasy.com/home The more effort you put in, the more weed you get out. It's also probably best to have your grow area sorted before you start germinating the seeds....
That would be weak led lighting for three plants and probably a frustrating waste of your time and energy. I only grow with led lights and have owned several in the past years. Some while ago I settled on the Calif Light Works SolarFlare 200. One for each plant. I originally tried two plants under a Pro Grow 180w led light and it just wasn't enough, at least for what I desire in a yield.
It's not about WATTS, it's about PAR umoles/m^/sec that makes or breaks a quality led One plant grown under a properly designed 100-150w led will outperform 3 plants grown under a non-mj specific led light, even if it's supposedly 300w+