If you have some extra $$$ (on the order of $250), you could start buying TE coolers. When I was an undergrad long ago, in my internship job we were cooling a focal plane on a satellite using some TE coolers [electracooldotcom] from the precursor of this company.

OR maybe try immersing the unit in ampcool or bitcool [engineeredfluidsdotcom] (again around $250) and use a recirculating pump from a fish tank over a decorative waterfall to bleed off the transferred heat from the PC into the environment