There are several options for watercooling, depending on how involved you want to get.
Koolance makes the best "fully-integrated" watercooling solutions. They're also pretty slick looking, with LCD temperature gauges and lights and stuff.
The
Zalman Reserator is another nice setup, with integrated pump, reservoir, and radiator. However, the whole unit is separate from your chassis, and because it doesn't actively cool the water, it probably isn't very good for overclocking.
If you want to do discrete components (which really isn't as hard as it sounds...) I recommend going with an
Innovatek kit. This is the setup that I used (with some extra accessories so I could cool my chipset and video card with water as well). The components are top-quality, and the basic kit has everything you need to get started.
here is how I've got my watercooling set up. I spent around $300 on my setup ($200 for the kit + $100 in accessories).
Just be careful, man...you sound like one of those guys that just goes "balls to the wall" and doesn't really regret when things go south. That's not inherently a bad thing, but it's really easy to destroy a $2000 computer should one of your water hoses leak, or you forget to turn your radiator fan on, or your pump doesn't come on, or any number of things.