Aside from FrozenCPU's issue there are other great watercooling e-tailers like Sidewinder Computers, Performance PC's, xoxide and the likes. I usually mix and match my purchases because
a| not everything is found in under one roof
b| the prices of one product may be overpriced compared to another site.
e.g: the FrozenQ res' I purchased were off of Performance PC's because i couldn't get the frosted call acrylic Flex tank on FrozenCPU while I picked up the XSPC Copper edition Raystorm from [strike]Sidewinder[/strike]PerformancePC's because said block was overpriced there. FrozenCPU on the other hand had favrable rad pricing and at the time they were the only american site to stock the Alphacool Monsta rads.
If you want to go with readily available resources that may come in handy and not require to stock them on your shelves - distilled water and silver kill coil. If you have alot of money to splash and can afford down time with making a batch of coolant from a concentrate then the Mayhems Dye's will be your route. The Mayhems isn't quite like the competitors though as they use suspended nano particles to convey their colors where as the rest use color/dye's/stains to get color in their loops. We do have a thumb rule though; anything that is a dye will always stain as this is the nature of a dye. You want color in your loop - then go for colored tubing.
Which leads me to the next point, if you're going with primochill tubing(color of choice) then naturally their fittings will be the answer. I wouldn't go with Monsoon fittings simply because they tend to crack exactly where they make contact with the lock collars. Reason, everyone is speculating, is due to stress fractures. For a D5 pump you're ID should be no less than 3/8" so 1/2" ID rigid tubing isn't a bad idea. Larger cases would look nicer IMHO with larger dia tubing and 1/2" fits the bill in that area too
There are other unconventional names in the world of watercooling like
a| Diamond cooling
b| Rocket science
c| Skeeper
and they all cater to making custom res', fittings as well as engraving services on your orders.
The other reason I mixed and matched my components is due to the immense amount of research and info I found that the combination of parts would yield a temperature I was satisfied with and it also went along the color scheme of my build.
^ more in my AMS build log(in sig)
* EX rads a re slimmer and thus will require higher RPM fans than the RX rads. Mind you XSPC launched a V3 of heir RX rads and they are better performing than the previous run. Thicker rads give you more performance out of low rpm fans and greater performance if you go with higher rpm fans.
Also have you decided on fans for your rads?