Buying 100 multichips without testing the spectral mix first is risky to say the least. My other suggestion would be to select a multichip and matching drivers that will give you room to dim individual colour channels 50% without compromising minimum PAR values. In other words, if your tank needs 100w multichipsfor intensity, you can't start dimming it down to 50% to get the spectrum you want.
This was kind of my point. I have no problem running twice as many LEDs at half power. I think it will also help with the shadowing you encounter with such a small point source. I just need to be confident I can get a color that is pleasing to my eye period.
My honest concern is the rendering of warmer colors under these emitters. This will greatly impact whether I see any need for lower Kelvin emitters. Obviously the Kelvin isn't everything as I've seen some incredibly yellow cool white LEDs that don't render pinks and reds for squat.