Copper vs. Aluminum

My plan is to talk with US Radiator, tell them my application and see what they recommend. It's gonna be around 1K no matter which way I go anyway. lol
I used them a few times in the past but the last time I called them to build me one for my duster I left it up to them to build me the best radiator for my setup. That's how I wound up with a triple pass desert cooler deal and had overheating issues at idle/slow cruise. I talked to the local radiator shop that used to do my recores (before the price of copper went through the roof) and they agreed it was a poor design. I bought a 3 core champion off ebay to see what difference it would make and problem solved, didn't have to change anything else.