Anyone using the DR120w grow tent? Help please!

Im thinking about buying the DR120w (4x2x6) but i have a few questions. I have a 400w HPS without an enclosed reflector or air cooling. I dont really want to switch lights for two reasons. I got this light for free and it is an HTG.com 400w light with ballast. The ballast is connected to the light reflector unit by a cord, but it is an htgsupply.com light set and i dont think i can separate the two, and i dont think i would be able to switch hoods anyways. If i can please let me know.

If i use this reflector what kind of cooling/venting setup do you think i will need to keep it cool? Also how many plants do you think I could get out of a grow closet that size?

If the DR120W gets too hot will the DR120 (4x4x6.5) stay cooler with that light since there is more space? What cooling/venting setup should i use in that?

Thanks!

the 4x4 will definitely stay cooler and can be cooled with a beefy computer fan with a 12v converter but you will need a some supplement ventilation. Most likely the 4x2 would work a FOAF used a 400w in a 2x2 and was able to cool it however it was mostly used during the winter and i feel like if he had continued through summer he would have had trouble. My suggestion would be to go with what you can fit in your space and grab a cool tube. The reflector with ballast attached will be even harder to cool in a tent. I love tents and swear by them, 2 minutes to build a grow room 5 minutes to take it down if shit hits the fan however cooling them can be tricky.

Yea im thinking about going with the 4x4 room now and buying an enclosed air cooled reflector that will fit my 400w HTG.com light and ballast kit (I dont think the cool tubes work with them). So your saying that if i use the air cooled reflector that most of my heat will be pushed out through that and a little wimpy computer fan can fix it? I was planning on getting a 6" inline fan for the reflector, and another fan to bring in fresh air.
Im not sure which one i would need. Which do you think?
I was thinking either:
http://htgsupply.com/viewproduct.asp?productID=52583
more for along the lines of power, or
http://htgsupply.com/viewproduct.asp?productID=46447
just to save money

Also which fan should i have bringing in fresh air?
And sorry for the ignorance but what is a FOAF?
Thanks!

yup just got a dr120w tent had to due to space restrictions were its located ive installed a 400watt lumatek
in a 120 mil cooltube with 120mil fan im pulling air from outside tent in across bulb and then ducting it out
straight, ive put in a co2 filter 100mil with 100mil fan aswell for odours and using ona breeze air purifier
im keeping 23.5c temp and 44% humidity outside temp is 22ish keeping an eye though on temps as the weather changes
so far so good 4 white russian doin nice

i would say get two 160 cfm fans and use one for intake and one for exhaust. try aghydroponics.com they have decent prices