HPS how close

As for the light i'd say no less then 1 Ft away.
And as for the fans what is the FPS(Feet per second) like the amount of air it can push.
it might be something different then FPS.

I only have one 6" fan and another smaller fan sittin right on top of my HPS to cool it a bit, and the plants are doing ok, however i keep my closet doors open ALOT of the time to allow cool room air to come in.

I personally have my 400W HPS about 2 feet away, any closer and the temps start soaring past 85 degrees, which is way too hot. A 2x4 grow space seems about the same to mine, check my journal out in my signature to see how i've set my stuff up. Good luck.

Here is an excellent light chart......make sure you do not start with the light too close, but slowly move it closer day by day so as to allow the plants to acclimate and not get burned.

lets see the inline is 250 cfm and the others are High Tech Garden Supply