Nice! how come i never find stuff like that?!? The dual CFLs do get fairly hot, so i would recommend going to a computer or electronic store and buying one or two cooling fans that run at least 30 CFM. I have a homebuilt 2x27 watt fixture over my 20 gallon using straight pin quad bulbs, and i have to have my fan running full speed to keep them cool. Remember, a cooler running temperature means a longer bulb life! 4100k is a fairly yellow. These aren't the best for plants because they don't have much light output in the blue part of the spectrum. Go buy some with a color temp between 5500k-8000k. most like 6500-6700k just because it is a nice white light with a lot of output. Good luck!
Ryan
Ryan