Taking the metal halide plunge?

[molybdenumman]

I have a 90 gallon reef tank with mostly soft corals and mushrooms. I am using the 4X65W coralife PC lights (260W) with and an extra ballast at 2X55W. I am considering moving into the metal halide lighting, but I don't know a lot about it. I have been looking at the comparable coralife light with metal halides (2X150W + 2X96W actinic PC). (No reason, just been happy with the coralife in the past.) Is the 300W of MH lighting going to be enough or should I consider going to higher wattage? There was also a question as to whether to use a 10000K MH bulb or a 20000K bulb. What are the advantages of each?

As I said, I pretty well have only soft corals in my tank. If I upgrade my lighting, I may consider clams. It would be nice to actually see my corals grow.

Any input you could throw my way would be appreciated.

DanTheMan