help with 1st grow cabinet

hi all,
i picked up a cab from home depot,the dimensions are 70'tall,4ft wide,and
18"in deep.
so my question is how big of light you guys think it can handle?i'm either gonna try to find a cool tube/substitute or buy a air cool glassed reflector which i will seal up and vent appropriately,for air extraction i will use a 120 cu ft/min bath vent/w dimmer switch.intake will be passive and odor control will be something similar to video's fan bucket with ona.
my first run will consist of 4-5(hopefully)skunk/haze hybrids.in 3gal pots.
ffof soil and ff nutes
i was thinking at least a 400w hps if temps get too high i can get a cheapie ac from wal mart.
all advice welcome/thanks in advance

400 hps should be fine to grow 4-5 plants, You should also get a 400 MH conversion bulb for veg.
Dont start your seeds out in a 3 gall. containor.
It will get hot in that amount of space, but intake and exhaust are needed.
How hot will it get? anyone else grow in that type of enclosure?

hey slip slide,
thanks for the input,can i ask why you recommended not starting seeds
in the 3 gal pots?
thanks.