First will start off with this build http://pcpartpicker.com/p/1i8Fc
then add in a full custom water cooling kit.
starting off with modding 2 of the new EXC-800 Portable 800W Recirculating Liquid Chiller into the case, block for the cpu and full cover blocks for the titans. fully done loop rounding out to $3500
Adding that to the $18500 computer for a cool $22000 is not a bad rig.