HELP! 150W VS 250W HPS in a 4.5 Cubic feet cabinet?

What would you recommend? there is enough space for 2 plants..
Also, does 2 x 120mm pc fans (60cfm each) will do the cooling job right?
One straight on the bulb and one for exhaust (or how would you reccomend to place them?

250w is always better, but space sounds a little small, what are the exact dimensions, so I can picture this. And PC fans are weak, son, get a honeywell air mover and pop it in the side of your box like an inline fan. works great for small spaces. Use it to evacuate air, and cut a smaller hole than your out take as an air intake, this keeps negative pressure. It's a large hole that can let in light, so make sure it is facing a wall wherever you mount it. Do not put it to close to the wall, or you will restrict the fan.

You can cut your air intake under the cab, as long as it's elevated off the ground with some kind of legs, that is one less spot for light to worry about. Make sure your intake and out take are on opposite sides. An out take should be up high to evacuate hot air.

id go with a 150 in a room that size then the computer fans might work.. i use bathroom exhaust fans for outtake and intakes there under 14 bucks a piece at home depot... divide the watts of your light by the square feet of your room.. 60 watts per "sq ft" is optimum...

4.5 cubic feet? What is that like 1.5 X 1.5 X 2? What are you going to grow in there?