If it was an original /6 car I'd use the 26 inch radiator and cut the core support. Then I'd look at a radiator with two cores and the biggest tubes you can afford.
Then buy a quality high flow water pump and a quality high flow thermostat. And the last piece of the puzzle is turning the water pump the correct speed. No SLOWER than 1:1 and turning the water pump faster than the crank is better. If you do all that, then the fan you chose won't be nearly as big a problem. I prefer a mechanical fan. Once you are moving at a reasonable jogging speed the fan is just in the way for the most part.
