That is alot of Novec fluid, maybe 2-3 gallons! (the cost of a D3).  Fans and heatsinks aren't necessary in a Novec closed loop system, i've seen better where the hash boards just lie flat on an aquarium bottom and maybe only 1/2 gal of fluid is needed.  In closed loop you still have to cool the condensing surface somehow.   Probably less efficient but a peltier cooler strapped to a large heatsink or plate might be less messy.  Not for dash, those things are energy hogs, perhaps workable on another coin, or if the one cooler rig is all you need for lots of hashing boards.

My exchanger/condenser thoughts lean towards a wort-chiller rig or plate heat exchanger with a DIY cooling tower outside to cycle the water.  But my first attempt will be to just pump and exhaust the oil heat directly.  Pumping water is better, as you are't restricted to the types of pumps that will do the job and not break down, but I think the small food-grade pumps can handle oil and are pretty cheap.  If you are after parts for your rig the automotive and home-brew industry seems to be a good resource.