True, white is a much more realistic representation of moonlight for freshwater tanks. I don't like the blues very much either. I just dim the same cool/neutral white LEDs that I use for daylight lighting all the way down for moonlighting.
I don't know anything about pre-made moonlight setups, but they mostly seem to be blue. You could use any string or handful of small white LEDs -- should be more than enough and an easy DIY project. You could power them from any old wall outlet cellphone charger--they mostly put out 5V which would be fine with appropriate resistor selection.