i'm planning to buy some some strong aluminum vessels,
probably two or three pressure cookers, cut out tops and unite them (more drawings to come) and have evaporators inside: the main freon "boiler", a copper block similar to a water block, would be in its bottom just over the CPU. Freon reservoir would go inside as an open vessel connected with hoses to the bottom of this aluminum chamber; there will be another chambers that will cool the video card connected with liquid and vapor hoses to this main chamber and there will be float valves in the main reservoir and in the liquid pools over CPU and GPU boilers.
All this will have to be tested before at around 265 psi at least (I have a brand new danfoss compressor for R404a, this is the vapor pressure at 40ºC, 104ºF). i read bowman1964 tests refrigeration systems at 350psi , i would try to settle at that pressure; I plan to buy a hand oil pump to use as pressure source for testing and a vacuum pump also.
I've been thinking about the best design for freon boiling plates but that is for tomorrow's story.
Edit:bowman1964 tests at 275psi and complete systems with compressors at 150psi