Water Cooling Rendering Computer Need Advices

Make that pump -> GPU -> 360 -> CPU -> 120 -> reservoir.

Distilled water, kill coil, a little biocide (e.g. http://www.petrastechshop.com/peptpcobi1.html). Don't forget a drain valve to flush the system from time to time. Avoid dyes. Since your system is 100% copper, corrosion protection additives should not be necessary.

It would be cheaper to put a single 480 at the end, but then I'd change the order to pump->CPU->GPU->480. The CPU will be running hottest no matter what, it would be better to put it before the GPU, to keep it a couple of degrees cooler.

http://www.overclock.net/t/584302/ocn-water-cooling-club-and-picture-gallery

If you dig through this thread enough, the general consensus seems to be that loop order doesn't make much noticeable difference to temperatures. As long as your reservoir is before your pump, I would say just hook things up in the easiest/best looking way. The water has so much thermal capacity, and is flowing so fast, that it doesn't change temperature much throughout the loop. However, hamster is correct in saying that CPU before GPU will make your processor slightly cooler, so it's not a bad idea. Since you are using a Bitspower pump top, you can use one of the extra inlets/outlets for your drain line if it is the lowest point in your loop.

As far as fan controllers go, also have a look at the Lamptron FC5v2. I'm using one on my computer and it works quite well. It has a solid reputation, and you can change the display color, which is nice.