I have read some of the threads on them here, or whats not in the buy/sell that is.
My fixture came with the usual 10K bulb. I have been looking at several others to get more actinic look, although I must say, my corals are starting to respond nicely to the 10K and the tank looks pretty good with it.
I have read on the Ushio 14k and the Phoenix 14k. Also the Radium 20k looks ok, if it was available somewhere.
Perhaps as long as the red turf algae stays at bay, I may stick with the 10K and see how the corals color up. My actinics are normals though, so about as good as night lights.