My light fixture is bolted to the rubbermaid with about 1" of space between the rear of the fixture and the top of the box. I just used some wood for support and the extra space so the fan can suck good. I just use stacks of CD's to to prop up the plant so far, so that the intakes don't get blocked, works like a charm, and I can just take a few out everytime she gets to close to the lights.

Also I did get a fixture designed for bathrooms, so it can get "damp", but the sockets are only 60w MAX so don't go out and put 6 42w CFLs in it or else you might start a fire. Anyways man I am pretty impressed with the box so far, I had a bit of a heat problem at first because I had put some nylons over the intake holes to catch dust, etc. Once I took them off its been 70-75* at 18/6, I haven't had the thermometer in there for a bit because I have nowhere to put it where I can read it from the top, but I am pretty sure its about the same. I am thinking of adding another 120mm fan to the inside to get the air moving a bit better but I'm not too worried about it right now.

Good luck man, make sure you post up a grow log when you get around to doin it!

Oh yeah also like I said before, if I were making another one, I would just paint the damn thing, the emergency blankets were a huge pain to put in. Just make sure you use enough coats to make it light proof.