The water pump is the easiest to find - just go to your nearest fish shop or pet shop and ask for a submersible water pump. It's the most expensive component in my water cooling setup. Get at least 200 gallon/hour water pump. Mine is a 270 gallon/hour pump, suitable for a water cooling system. Such submersible types indeed do heat up water a little, by 1-2°C.

The box of the water pump

 
Water pump in action

Many of my friends ask when they saw the water, "What the hell is that yellowish liquid?". It's just normal tap water with some anti-rust. (In the picture, it looks like white, but in real life, it's yellowish)

This is the anti-rust liquid I use for my water cooling system

As you can see, the water block is welded, which can't be done on copper. This is the reason why steel was used. It's painted with red oxide anti-corrosive paint. I didn't paint the contact part, just in case it acts as an insulator. See that custom made clip? It's made of the scrap metal from the casing that you get after you plug in your PCI or AGP cards. I'm getting a new water block which made of stainless steel so I will be able to get rid of the anti-rust.