Will I have temperature problems with a 600w?

[toothbrush?]

I've been planning this SOG grow for quite a while now and want the biggest, tightest buds possible. I'm wondering if I'll have temp problems or if a 400w would be more suitable. The 400w would give ~59wpsf and the 600w would give ~88wpsf. At what point are the benefits of more wpsf diminished by cost and use by the plant? I've read that the difference in heat will be significant between a 400w and 600w but does using a cool tube and 424cfm inline negate this?
I will be using a 2.5'W x 2.5'L x 5'T Homebox grow tent (~6.9 square feet)
600W digital HPS ballast/light WITH COOL TUBE from HTGsupply, which will be vented out the top to another room
Attached to the cool tube will be a 6" inline fan rated 424 cfm (also from HTG)
Two of these: http://coolerguys.com/840556021698.html . One intake for the bottom hole and one exhaust for the other hole at the top of the tent.
The room outside the grow tent will be 70-75*
I'll have between 25-36 plants in 5" hempy buckets (clones straight to flowering at 3") and I don't expect the plants to reach over 16"

Thanks for any help!

 

[Roken]

You should be able to keep the 6oowatt H.P.S cool enough with the air cooled housing's. I run 4 total 600watt H.P.S and since they are air cooled i dont have any problem with heat. Just remember to have enough fresh air coming into your grow room at all times, and to have a seperate fan just for extracting stale air away from your garden. Keep us posted and if you can post some pics. Peace and Love!!!!!!!!!!!!
Roken.

 

[Growdude]

400 would work great, more than enough for 6.25 sq/ft
Also 600 watt bulbs are odd balls, I know all the hydro shops carry them but there the only ones that do, its way more expensive than getting 400 watters at the electrical supply houses.

 

[toothbrush?]

Would the yield gained by using a 600w instead of a 400w be significant with such a small area? ~59wpsf vs ~88 wpsf... hmmm... I don't think penetration would even be an issue, since they'll be flowered immediately after cloning.

And does anyone know how much more effective an enclosed cool tube system is compared to a system with ducting only on one side of the cool tube?

Thaaanks