Been told something different every time I go to the hydro store

So I'm going to be ordering and buying my new setup in the next couple of weeks.
The question that I still have though is what light/s should I use in a 2x4x5 tent. I've been to the hydro store a few times and gotten different answers every time ranging from 2 250 hps, 400 hps or 600 hps. I was thinking cool tube but unsure of the exact setup with tubing and fan/ filter ecspecially when the place is a closet with no accsess to constant cool air. One of the workers did mention a all in one ballast light that can be cooled through the top with tubing. I'm looking to do a scrog type setup and need to cover 8 feet which would be covered by a 400 but the tent may be a bit wider then the reach of the lights on the outer edges. So that's where the two 250s come into play, any ideas and a mock up setup with fan and tubing ?

Lets deal with lights 1000w will do 4x4, 600w 3x3, the 600 is the best bang for the buck as it puts out more for it's size than a 1000w it just does not have the same penetration. You need to decide on how big a plant you will grow and pick your light. I use 1000w and 6000w and 400w, the 1000w lets me grow a plant about 4 feet anything lower than 4 feet gets no light, so I grow 3 to 4 foot plants with 1 foot bare from the ground up. I lolly pop them for many reasons. My 600w I grow them 3 feet high with 1 foot bare.

Don't believe the manufactures or shop's claimed. After your first grow you will know what I mean.

You want to run at 76 degrees and 60% humidity with lights on so your going to need cooling no matter what you use. The 600 again is a good choice for that. A cool tube is great but what most people don't have is a degree in thermal dynamics so what your doing is transferring heat from the light to the tube which holds it, heat sink. Try with a gull wing and just vent the whole box from the top, Heat rises. If that don't work for you go by the tube.

Cooling: you have 40 sq feet so you need a fan that will suck all the air out in 1 min. But when you add stuff (filter) or but bends in the line your looking at 100cfpm fan or get a 4 inch with a speed controller.

Get an electronic ballast or an old style, just make sure you keep it out of the tent.

600 hps all the way with a
get this system its pricey but way worth it after first grow
600 watt phantom ballast (ballast is dimmable and has a micro chip sensor in it to detect mh or hps)
Xtrasun 6 hood (cheap awesome and air cooled)
hortilux bulbs (best of teh best)
Valuline 6" centrifugal fan
6" ducting

oh and ratchet ropes they are way easy to use and hold 75 lbs