I would go with a higher wattage bulb if I were you. I say this as I've been there done that, and eventually, if you ever decide to go with clams or
sps corals, you will need a higher wattage bulb.
I would AT LEAST go with a 250w 10K bulb and a 400w 10k bulb would be much better. I've had 10K bulbs, and the Ushio brand gives a very nice white color. Personally, i think that 12k bulbs are UGLY as H#LL and even blueline 10k bulbs are too fake blue.
I also agree, DON"T go with a 6500k bulb unless you go with the 250w or 400w iwasaki, and then I would supp it.
Buba