A 3x3 enclosed space will heat up like the sun -- unless you ventilate air out. Just hook up a fan that blows out of the closet to an attic or a dead space in a wall. It'll make it work. If 1000w is too hot, try a 600w instead. (Or 2 400w).
For a 3x3 space, I'd do an ebb & flow with rockwool. Fast, easy, under $500 to get everything up and running minus the light. Post any questions as they come up and we'll be here to offer the best advice we can........... Good luck man........
Also, with a 3x3 space, dont even keep a mother. Its a waste of space and you cant flower and mother in the same space (They require different hours of light, 18/6 for mommies/veg and 12/12 for flower). Just pay the $7 each for feminized seeds and I'd keep about 9 plants in there at a time. That's at most 10-12 seeds every 2 months.