Try going to the "Vertical" thread and see what they are doing with basically "side lighting".
You may want to reverse things and put the plant in the middle and the 3 bulbs around the plant down low (about 1/3 from top).
Keep or make movable walls to reflect the light tight to the plant. I did something similar with a child's Hula-Hoop type plastic ring,, shower curtain hangers and hung Mylar off the hoop. Sort of like a lampshade around all. Keep it tight and close.
I did this to get a handicapped person started (card holder) and it was great for him learning and easy for him to work. I set him up with Autoflowers to start because they don't require 12/12 or light tight areas during flower. But, in a dark closet or something it should do well with photoperiods.
Instead of Mylar you could get a space blanket from Wal-Mart for $1.00 and be better than nothing,, but the Mylar is 10X better. A lot of light passes through the space blanket and is not as well reflected for using.
Could also make movable walls using white poster board to contain the lighting.
Leave a gap at the bottom and the top open and the natural convection will keep it cool enough to get by.