Based on a 4X4X6 room (sorry I guessed at height)
Minimum Lighting 25 watts Per Square FootLighting
The minimum recommended lighting for your area is
400 watts
Ventilation
The minimum flow rating of your fan should be
80.0 Cubic Feet per Minute (CFM)
Power Requirements
This setup will require
4.3 amps to be available at all times for safest operation*
Optimum Lighting 40 watts Per Square Foot
Lighting
The optimum reccomended lighting for your area is
640 watts
Ventilation
For optimum ventilation the flow rating of your fan should be around
88.0 Cubic Feet per Minute
Power Requirements
This setup will require
6.9 amps to be available at all times for safest operation*
Maximum Lighting 60 watts Per Square Foot
Lighting
The maximum reccomended lighting for your area is
960 watts
Ventilation
Going this way you will require a fan with a flow rating of at least
104.0 Cubic Feet per Minute
Power Requirements
This setup will require
10.4 amps to be available at all times for safest operation*
Additional Comments
Getting to these points and or over it is highly reccomended the grower use Co2 in their room as your plants will only be able to photosythesise a certain amount of light before needing a Co2 boost to benifit
I think you could get away with the 1000 Watter properly cooled... The program I use for calculating grow rooms doesn't take certain variables into concideration...
You could always make your room 5X5 and the 1000Watter is optimum.