If you really want to save some money on water cooling then make a system yourself. Its really not that difficult, and I will be happy to guide you through it. You will need to find a good waterblock, other than that you can get the rest of the equipment at a good pet store. Any aquarium pump with a flow adjustment will be cheaper and better than the one you will get with the average water cooling system. If your interested in building one yourself, PM me and I will give you a parts list. I can tell you that other than the Waterblock, the rest of the parts cost around $45.00 - $60.00 US currency. There are many advanteges to building one. The one that stands out to me is the fact that you can cool multiple systems with one pump. I went a little overboard on my latest rig and also purchased a Whirlpool Countertop water chiller. It has a 6 gallon capacity "Hows that for a resivoir" and also cools the water. This means that the water gets cooled through the raidatior and then the water chiller. You can do away with the Radiator and fan altogether if you use a Water chiller, but I use both. My temps are really low, they have dropped under 20C. This cost me an extra $69.00. The original system that I bought was the Thermaltake Bigwater liquid cooling system. It was around $159.00 including shipping, however I saw the same system for $170.00 on the same website "Newegg" today.
If you want to see some impressive photos of a water cooling rig, look at Folkens link.