GD is straight to the point. hear him out, take notes, and listen to or not listen to him. Most of the time he is more right about Subaru's than anyone else you'll find online. He's like a bunch of us, and owned and knows all about $200 Subaru's. I promise he's not judging you, he's just been around hundreds or thousands of them and knows most people don't spend that much to maintain them or waste time upgrading, turbo charging or other wishful thinking type initiatives. if you're an outlier, and want to put forth the time and effort, then no big deal, he's not forcing you to do anything. Just move on to the next reply.
I'd recommend aftermarket too, they're cheap, last a really long time, and aren't prone to damage unless the car is being constantly beat at which point i'm not sure i'd want to install a more expensive aluminum. I get it - i've looked into aluminum before too - it's a lot of time figuring what works, fabrication, etc - time that in the long run is better spent on other issues you'll encounter in the next 10 years.
In general it's not common to install aluminum radiators in that era. 95-98 legacy radiators should all be the same - you can do a parts search online and see what vehicles a 95 radiator fits. that might help expand what you're looking for as you search for the closest fit you can find. The fan mounts, lower legs, and radiator hose locations and diameters change over time and are the parts that require modifications if you find one that physically fits in the location.