I bought a basic oscillating fan for a tenner and pointed it at my 400watt hps and its keeping everything at acceptable temperatures and clears the hot air from the space between the hps and the tops just fine.
not sure yet on heat light should be here on 9/21 i have 6 plants in veg under 6 cfls in a grow box 18 by 30 by 4ft the flower box is same size but useing this light this is my first indoor been outdoor 15yrs sun is a lot easer lol