I was thinking about doing something similar. My biggest issue is where to reject the heat to. My PC is in a small room and as a consequence the PC heats the room up by a good 8 - 10°C over a couple of hours of gaming. No matter what method of cooling I use (active, air or anything else) the elevated ambient temps are going to have a drastic effect on case temps. This will become worse if I go with my original idea of running a compressor to effectively air condition the case and cooling fluids. I'm not sure if its something that will affect you, but thought I might share anyway!!
The only thing I did think of to get round it was to reject the heat under the floor boards, hence effectively removing energy from the 'room' system. Not sure I'm ready to plumb my PC into the house yet though!