x o x
x o x
x o x
-----
x=4x4 space with 1000 watt lamp
o= 3 foot space for tending.
-= 2x8 ft space to enter the room. (assuming door is near this space)
you will want to put up "fences" around any space that you need to walk. they will keep your walkways clear.
It will create a lot of heat.
The "how much" heat, cooling power, air cool power you need all depends on your climate, insulation, and so on.
I would use the Vortex 747 cfm fan with a speedster fan speed adjustor to cool those lights. with a speed adjustor, you can have whatever you want up to 747. Also, large fans ran on a low speed are sooo much quiter than a maxed out fan. But you will probabyly be running 75-100% speed. Obviously this design is for a closed air cool circuit. (glass pane in your reflector).
Two different air cool circuits pulling from the outside that connect to the 747 Vortex with a Y piece. Hopefully your hoods have 6 or 8 inch flanges.? If they are 6, you might be able to find a 8in duct > two 6in duct (Y piece/reducer).
x o x
x o x
x o x
l . .l
. Y
747
BTW, if you have little experience setting up and/or growing, this could be an overwhelming task. But totally possible. If you are going to go this big indoors though, you can't go cheap on some things. Fans and cooling will be one of those things.
Im working again, so not on as often. But if you have more questions, shoot.