companies like koyo and mishimoto should anodize there radiators black. i would be all over one of those. i was cruising the net and found this custom one done from this company called mark 7.
thought about contacting them to just do a dual core to the exact specs of any other dual core civic rad but in the black. quote from the webpage "Mark 7 Radiators can build you an aluminum radiator, specifically for your vehicle, for less than most off the shelf generic radiator suppliers." i might further dig into this over winter.