I would definitely go with Dan's aluminum radiator, especially if you can get it for around $400!
While you are at it and have the thing out, you can improve your cooling with a larger aluminum fan in place of the heavy "shovel" fan on our cars, which can make things run hot with A/C on in Dallas rush hour traffic or a crowded Cars & Coffee parking lot, and without the need to put it in neutral and rev the engine... or better yet, aluminum radiator and an electric fan, which will eat-up the heat even when the engine is not spinning very fast, yet will not create unwanted drag at highway speeds. Plus it takes less engine power to create the electricity for said electric fan versus spinning one mechanically, so you may get a little extra pep out of the mod.
I'm running one of these in my Duster currently: https://www.summitracing.com/parts/flx-1017/overview/
I can't remember the exact degree difference, it kept my car from running hot while waiting for 30 minutes for people to get out of Cars & Coffee.
If I'm wrong on anything please feel free to correct me, anybody.