Ok guys, hope you can deal with the heat then. Look at the cubic feet too I just think that if the plants starts off 12" off the ground and normal 30-45 day veg the plant will be about 3-4' tall plus the 12" to start with. Add some flower time where they stretch and you have a 5'10" plant or so and no room for the light to go up anymore and displace the heat.

I was just thinking about the room above the light to help displace heat is all.

Good luck hope it works out great!!