Actually, I would custom design the cooling system myself, it would be a heat-exchanger system based around liquid nitrogen and would cool a central radiator like in a standard combustion engine in that the coolant would circulate around from the heat sinks that are attached to vital components, such as the CPU, GPU and chipset, north and south bridges.
There would be a central large cooling radiator for which I would have a one or more 120mm, thermal fans so that the ambient air temp stays frosty

The other thing I would do would be to have an elevated floor for my computer room. The floor tiles could be lifted to reveal a crawl-space where tempurature controlled AC is feed into and thru my custom rig and out thru the top and back behind the walls for a return thru the heat exchanger once more.
Of course the custom chassis would be sealed so only the cooler air gets into the bottom of the chassis before the hotter air gets exhausted thru the top. I will also isolate vibration and noise via dampeners and dampening material to attempt to eliminate as much fan noise as possible.
I'm thinking I could make up both a P4 Extrem Edition and an Athlon 64-FX rig. Of course with the Athlon I could go with an SLI config or get Gigabyte's new Combo Motherboard + Dual-GPU graphics package