a great option is a cool tube. They work amazingly well.

a buddy of mine has a 1000W hps. He has a 165cfm fan going though a cool tube, which removes a hell of a lot of heat (its the only exhaust). and then a small 90cfm fan as intake. and his temps are fine.

without a cool tube your going to need to buy a bigger fan, which can cost a lot. as well, cool tubes still work well when the intake air is at a higher temp. So if the room your wardrobe is in gets warm, in summer or w/e, a normal set up wont do you much good. it'll get hot inside the grow room. (happens to me). With the cool tube it will remove practically the same amount of heat no matter what the intake temp is.

This is because the bulb is like 1500 degrees F. so a change from 70 to 85 F dosn't make too much difference.