I am going to give you a good $400 system, 1/2" ID tubings/fittings
Well, for the pump I would definetly go with DD's Variable speed. It's very powerful, and nearly silent when you want it to be. And extremely powerful with a slight noise that can only be heard with the case open, and super high flow.
DD12V D5 Variable Speed
For the CPU water block, I'd say that if you want that Apogee GTX then go for it, I hear nothing but good about it.
Swiftech Apogeeâ„¢ GTX CPU Waterblock
For the GPU block, I personally think the koolance one looks a bit better in general, but in my soon-to-be black interior case, the DD one will look sweet. I've also heard that the DangerDen one works better to cool it's surroundings, while the Koolance one does an OK job. They're both SLI compatible, and both do the job. DD's will run you a bit more, but I think the added performance is well worth it.
Koolance's DD's
If you want a Northbridge block, go for it. But most chipsets come with highly intricate heat syncs and such, such as the Asus Striker Extreme, so I see no reason to add one. I'm not to knowledgeable in this area since I've never WCed my chipset.
The resivior doesn;t really affect performance, pick whatever you like best in this case. However, some people prefer the drive bay format so they can see the water level right in front of them, plus, it just looks cool
DangerDen's 5.25" single bay res comes predrilled for 2x LEDs so you can see the level. They also sell a version about 20 bucks cheaper that's just a cheapy old High Density Polyerthane model. They all get the job done.
All that's left is the radiator. This is where quality is critical, since this is where you rid yourself of the heat.
Thermochills are pretty good, but very expensive. I'd prefer getting a
BlackIce GTX or even the
Pro version (X-Flow though). Pro's are cheaper, by a lot and the GTX is only a bit more efficient. I myself would get any of the 240's, because 1 fan is no where near enough, and 3 fans is too much, i'd have no where to put it.
Coolant is also important, as it's your means of heat transfer. Nothing with glycerol base will do the trick, nearly as well as just plain distilled water. I like the MCT-5, it's non conductive, doesn't stink, and won't stain the tubing. But really anything will do, as long as it's a good non-conductive and non-glycerol based. UV reactive ones are cool if you have a UV light. Generally anything under $20 a bottle (32 oz.) isn't worth your time.
I'm sure you can handle your own thermal paste -cough AS5 cough- and tubing. Make sure to order some tubing clamps. I always put two clamps per connection for added security ^^. Also, pay attention to fitting size, this set up is all 1/2" ID (Inner Diameter), I've seena lot of people screw up and have to send stuff back