How much space do you have to play with? What about making your own chiller out of bar stock, making #rotor blocks, for which you only need a drill press? The concept I was playing around with was to remove 500ish watts of heat, from Dual Opterons and Dual SLI Geforce 6800 Ultras, but was canned as I decided I'd rather go on vacation than do sub ambient cooling on that scale
