In this tiny space, is your vertical set-up more conducive to growth then an overhead set-up? I am aware of the benefits of going vertical but i have never seen it in a small space.
I am working on a cab (4T x 4L x 3.5w) and have a Fresca sol 600 w water jacket cooled light going in there. Have you ever thought of using the water cooled lights on a vertical grow?