Were you thinking something like the Koolance PSUs?
http://koolance.com/1000w-liquid-cooled-power-supply
If so, they aren't great PSUs, and they only include a small pump, you would still need to drop another $300 on the blocks, reservoir, tubing, and radiators. It does NOT cool the CPU by itself, it is only meant to be part of a much larger system. There are NO PSUs that can cool the CPU, they aren't in a good position to, and you really don't want to be dumping a ton of heat into your primary power regulation system.