Lighting Recommendation

Hi Fellas

I am upgradinga small private closet that shares several obstacles ,water heater ,a/c condenser ect.

Its about 3.5 x 4 ft of usable space with a small L shape at one side

its 6 ft from the bench i built to the ceiling . Previous attempts of clamp on florescent lights and tube light fixture gave inadaquate yeilds and growth.:(

So i am ready to step up and purchase a decent HPS lighting fixture and ballast. And plan to ventilate the room in and out to keep temps down.

So my question to the experienced growers with limited funds...
CAn I get away with a single 400 watt cool tube HPS hung from above and if have too rotate the plants daily for best exposure.

I was thinking of putting my tube flor. lights vertical in the corners of the closet in addition . A 250cfm 6 inch fan would provide the air exchange thru the bulb tube.

So my number one issue is temp control (keeping it down) i can always cycle the cool tube fan with timer to manipluate the closet temp. Or add a small space heater this winter if needed.
Second issue is not going over 250 -300 bucks. Light hood bulbs ,fan ducting. everything .

Anyone consider used lighting or best to start with new stuff??

Also can i veg under the HPS or do I need the other whiter bulb ?

I thought it out best as I could - Your perpepectives please

Thanks forum members
D.