Has anyone installed the Airflow System A/C unit in their RV-14 yet?
As for the ice chest coolers, based on my experiences with one in my Grumman AA-5, they are not worth the effort or cost. I gave up using one I bought a few years ago at Air Venture after just a couple of uses, as the ice was completely melted in the first 15 min., and getting the ice chest in and out of the back of the plane, particularly when full of melted ice, caused me to overheat more than the amount of cooling that came from it during flight..
Scoop or no scoop?
Since I most need cooling/dehumidification during ground ops with the engine in idle and not moving or moderately taxiing, I think the actively cooled condenser will give me better performance on the ground then the external scoop. There is of course greater potential for CO entrainment that must be considered, but without the potential loss in aerodynamic performance.
Power considerations
What I've seen so far suggest the typical compressor will consume around 4-5 HP and 15-20 Amps in a 14 V system. The IO390 should have plenty of HP to spare and 70 Amp alternator should provide the electrical power needed, but the latter still needs to be confirmed.
Congrats on successfully completing a quite complex modification of your airplane. Did you happen to do before/after weight gain and CG deltas?