Yea, that height seems pretty unmanageable.
If your containers are 12-18" tall, and your light is 9-12" plus ~18" of space to prevent burning the plants, that doesn't leave any room for the plants..
Even growing in small containers, and cooling the light to the point you can keep it say 9" off the plants give you about 12" of growing space at the MOST.
Not saying it's impossible,but I think you're going to have to get pretty clever with your set up, and do something pretty unconventional to make it work.
Maybe a vertical ScrOG opposite laterally moving light movers or something similar. But then you have an entirely different host of issues to play with...