enough space

I have a closet that is 4 1/2 feet by 2 1/2 feet and 8 feet high. I have 5 ice plants in veg, 4 NL seedlings and WW seedlings. I also have 3 plants in veg that are just bagseed. My plants are in a different area because my closet is my flower room. I just got given a 1000w hps light and I really want to use it, but I need to find a way to keep my closet cool. So I need some suggestions. I also have two questions. How many plants for a sea of green could I put in my closet?(the most I have put in there was 3 at a time.)
And would a bathroom fan in the wall beside the light then vented through the roof vent enough heat out of the closet?(the ballast is kept outside of the closet.)

come on, no one has any suggestions

Probably not much coming from a noobie, but I can only offer these suggestions:

center the light oon the wall, maybe even hang it a bit lower, so that it's not as close to the walls.

Maybe stock up on an extra fan?

I'll keep thinking, but I'm not sure if I'm ever going to work with that many watts so I'e never considered it.