Okay, you've got things covered, so no one has to tell you DON'T SKIMP ON A BURLY BLOWER! haha
600 HPS is most lumens per watt. Get the best bulb you can afford. Cooltube in cellar is probably overkill, although you will still benefit from an air cooled hood. If you have $$, 2 HPS600 is WAY WAY WAY better than a HPS1000.
Grab a big slab of foam insulation board for the floor. Trust me on this. Plants with cold feet complain more than a kid with wet socks on a ski trip.