Two sources for Airpots
http://www.growers-inc.com/03ap-k13ea.html
http://www.calgrowers.com/index.php?app=ecom&ns=catshow&ref=airpots&sid=765qrds6532bfjrh1z0un5u1ag0x521i
Accepted rule for lighting is 50 watts per sq. ft., you have just under 12 sq. ft which = 600 watts
600 watt is also the most efficient bulb, that's what I would do.
If the air is already scrubbed with the carbon filter, dump it in the house to recover the heat.