I just got a light from there. I got a big one with 4 T6 bulbs. I didn't need that much light, but it was cheaper to get it and only run 2 lights than to get a little one. From my research and advice from George... I got the one that has pink and white bulbs. It is working very well so far.
That place does have really good deals sometimes.
Ususally the blue and white is used for salt water, and the pink and white is used for fresh water. The blue light tends to encourage algae growth.
I hope this helps some.