Hey PurpleSkunk, neat beginnings of a little set-up you got there. (4) 42 watt CFL's are about 11,200 lumens which puts you at about 4,800 lumens per square foot. That's close enough to 5,000 for me. I would evenly distribute all 4 lights at the top of the box and train the plants with LST to have a flat canopy 2 inches below your CFL's. You are going to get better results of reflectivity if you painted your box interior flat white and stay away from aluminum foil. A quart of paint would do your box fine. If you painted the sides and the ceiling white, you may be able to eliminate your aluminum reflectors you got for your lights and gain much needed height, IMHO...........
In a small box like that, I woud surface mount the lights to the ceiling, and raise and lower the plants by a system of blocks that could be stacked for any height combo. With cfl's you want the canopy to be 2" away from the lights at all times.
At about 2.35 sq ft, you will soon find that 6 plants will overrun you quickly. Your space is about good for 1 or 2 mature flowering plants. You'll see they fill out the space quickly and will get tangled up and scraggly packing more in there than that.
I was where you are now about a year ago. I started something like 56 seeds (bagseed) on my first attempt. It broke my heart to eliminate all them but 4 which is all I grow at one time for my needs. Keep reading and fine tuning your box and grow. You'll do fine. Good luck
Good luck - so far so good.
PB