I think larger watt cfl bulbs put out more heat than multiple smaller watt bulbs, they take up less room too. I am dedicated to running the smaller ones. If your going to buy bulbs look for a Kelvin temperature and lumen rating, if they don't list it don't bother. You can find the 6500 kelvin 26watt GE at walmart. The other ones I got at a local hardware store. Those bulbs are Sylvanias. Try looking online for an economy pack for the sylvanias, great price for great lighting. As for the room it is just a 4x6x7 in a dark corner of the basement where no outside light enters. Thanks for the interest. Are you doing or planning a CFL grow serpentine?