Deciding on Cool Tube Set up... Help!

I can't really decide what set up I want to go with. My space is 2.5x4x8'. Tent and all. I've narrowed it down to these 3. What do you think will be the most beneficial and realistic for my space. Not really too worried about heat with the cool tube and I have two 4" fans rated at 170 cfm as well as oscillating fans. This is also for 6 babies... Thanks!

400w HPS COOL TUBE GROW LIGHT 400 watt Sodium Cooltube - eBay (item 180127387721 end time Oct-26-08 13:47:09 PDT)
600 watt HPS GROW LIGHT w COOL TUBE 600w hydroponic wat - eBay (item 180127392263 end time Oct-26-08 14:01:25 PDT)
COOL TUBE 1,000 watt HPS GROW LIGHT 1000 1000w Sodium - eBay (item 180127392284 end time Oct-26-08 14:01:28 PDT)

I think the 600W for your space would be most appropriate. Your fans wouldn't help much with the 1000W system, and the cool tubes would likely start smoking