Matt,
My experience tells me that water cooled systems are more expensive, more prone to accidents (water leak and a fried computer!), more hassle to setup and about as effective as a proper air cooled system.
I would stay away from a water cooled system, and guess what? The water is cooled by a fan anyway! Also, the money you spend on water cooling could be spent on better parts
Processor sounds good anyway, I would personally go for an Nvidia Card, but ATI and Nvidia are about neck and neck I'd say.
Also, to keep the costs down if you want, buy 4GB RAM first, as you can always upgrade later if the mobo supports it
dont get the water cooling system.
if the fan breaks you can replace the fan...
if the water cooling system breaks... good bye computer
also you will need the right version of Microsoft Windows...
as some are there just to change some things (like comands)
BUT you will need a full Version of Windows. also Microsoft Windows XP is discontinued and there is support till 2014. Vista is not to good. Windows 7 i will say as the support of the computer is longer and there will more years till there are not much software getting made for it.
good luck mind you
Captain cadet