I am having the same issues with releasing heat in a small space. I have a 400w MH running in a tent 36" X 20" X 64"...I already have 4 seedlings in my tent running under cfls. I tried to switch to my MH but the internal temp got to 95F (with the fan) so I switched back top the cfls and I am now going to buy a better fan than the one that came with my kit.

I am interested to see how you bring the temp down under a 1000w HPS.

So you are only using cfl's for vegging??