Personally I would have paid the little extra for the Liang DDC with variable control (think its the swiftech or something).
Also might want to know whilst distilled sounds like a good idea - I'd recommend reading the warranty on the EK waterblocks. I used to use distilled for a while until I seen they had changed their warranty to indicate they only recommend their own EK coolant - since which I've switched to that stuff.
Never been one for coloured fluids as just like you've researched it clouds etc - so I've just gone for coloured tubing aswell.
enjoy - plan it carefully as you'll find you need extra bits here and there once you start setting it up! (i.e. angled fittings etc)