Well, I will try to answer you. I've owned an heating, ventilating and air conditioning company for about 10 yrs.

First off, if the ambient air that is drawn INTO your tent is 90F, there is no way to do this without using A/C. However, if it is normal room temperature, say 70F, then you should be able to get your inside temp within about 10 degrees of that (around 80F). You have 2 1000W lights that are putting out 6,000 BTUs. A lot of gas fireplace put out 15,000 BTUs, trying to heat a house, and now you have almost half of that in a little tent 4ft by 8ft. I'm just trying to show you what you are up against.

Without using A/C, and assuming your 'cool' air you are bringing in is about 70F, you will need vented lamps. If it was me, I would hook both lights up in tandem, bring in cool fresh air from where ever you can get it, and PUSH it through the lights, and then directly out. By vented lamps, I mean the ones that have the glass pane under the bulb so the hot air is instantly blown out with constant fresh cool air rushing thru it. Then I would put my second fan up as high as I could inside the tent pushing the air up there OUT, since hot air rises.

Then I would put a passive (no fan) air intake near the floor to let fresh air (cool) into your tent. Since its passive, it will need to be about 3x bigger than the size of the hole for your fan. Since you are constantly pushing air OUT of your tent, the passive inlet will just replace the warm air being pushed out. Then place a fan or two inside your tent to move the air around.

None of this, however will do anything to scrub the air. So, depending on your situation, you might want to consider installing a charcoal filter (or scrubber) on your exhaust fan that changes the air inside your tent.

IF you do this, your tent should be about 10 degrees warmer than the air coming in. Good luck!