A general consumer should not be doing water cooling, too many things can go wrong with it leading to catastrophic failure. Since you built it, you would be to blame. That is if the cooling company didn't have some sort of manufacturing problem. You will get a very powerful PC in that price range. Below is the most powerful PC I have ever put together that will meet your needs and budget. All items come from Newegg.
Case:
APEVIA X-TELSTAR-RD Red/ Black Aluminum ATX Full Tower Computer - You need a full tower case to fit in the most powerful video cards. This is a very good looking case. $159
Motherboard:
ASUS P6T Deluxe/OC Palm LGA 1366 Intel X58 ATX Intel Motherboard - This is a motherboard that supports the latest Intel processors, the i7. One of the features of this motherboard, is that is allows for both SLI and Crossfire. It also uses DDR3 triple channel memory. $338
Hard Drive:
Western Digital Caviar Black WD7501AALS 750GB - Get two of these, they are only slightly more expensive than a 500GB. ($89 each) $179
GPU:
SAPPHIRE 100251SR Radeon HD 4870 X2 2GB - Get two of these if you can afford it. This is the absolute top-of-the-line card...for now. It's huge, powerful, and expensive. ($499 each before the mail-in rebate) $999
Power Supply:
CORSAIR CMPSU-1000HX 1000W - A high-quality power supply from a very reputable company. You need as much power as you can get to run all you've got. $259 before a mail-in rebate.
CPU:
Intel Core i7 Extreme Edition 965 Nehalem 3.2GHz - This is the most powerful processor you can get. It has a very high clock-speed and is easier to overclock. This processor is new, so there aren't many good heat sinks available for it. The stock cooler is still good, the only real reason to overclock this thing is for bragging rights. $1,029
Optical Drive:
LG Black Blu-Ray Combo Drive - This not only allows for writing and reading of Blu-Ray's but also all the DVD and CD formats. $229
RAM:
G.SKILL 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 - Get two of these. You need three memory sticks for triple channel memory. ($214 each) $429
OS:
Windows Vista Home Premium 64-bit - You need a 64-bit operating system to use more than 3.5GB of RAM. $99
$3,727
This post has been edited by DJBPace07: 07 December 2008 - 11:15 PM