Just tossed my oem radiator out due to a near impossibly complicated back yard, shady tree, (-14 degree, wind chill: -40 degree), fix situation, and a near total replacement of the fins would also be required since the fins were really rotted out at 215k. It was brass tanks, with copper fins. Have no desire to become a radiator mechanic, nor send it out for a fix as the cost would've been more than an aftermarket replacement. Seems most are made by china laborers. Ordered an aluminum replacement which is 'iffy, but good enough perhaps to get a few plus miles ahead. Even the best USA made radiators seem to be 'iffy according to some results I've seen. I think that Modine is now mostly china made now. Griffin, although expensive is probably the best bet, but one can toss the coin on that too according to some pissed off buyers have reported. Face it.., it is getting hard to get quality parts now a days. Seems everyone is tossing the coin as per longevity. Figure I might even get one of those cheap commie plastic radiators as a spare, in which to toss on the roof top for long road trips.., just in case.
The aluminum radiators will degrade with the green stuff, and require the orange anti-freeze. John Deer makes a 50/50 mix which is handy. Yours, just use the green stuff, as it is what is oem recommended. Most anti-freeze stuff in Alaska now has a bitter chemical in them so that animals will steer away from lapping puddles of it. About freaking time.., although I have no idea how re-active the bitter stuff, (chemical, or organic), might have against metal parts of any kind, or not.
There are different models of Napa accessories in question. Always get the best. On the other hand some claim that there are even better built, near, at, or better than oem. Go with them. Rockauto.com is one good place to look. Forget which water pump I got as a spare from the 4 wheel drive.com guys when I ordered a slew full of extra parts a couple of years ago, but if I had to do such over again, I'd do what you are doing, and seek further advice. Seems Bosch is a favorite for a lot of stuff. 2.5 years is really weak. Seems that Ga. driving environment is ok for a couple of years between flushes. Some scum might actually be some extra layers that might be preventing radiator leaks. Pitting could be caused by tiny foreign objects, or some spooky ph thing, lol. Do you have a shop do your flush? If you do it, are you opening up your lower engine block port during the flush? Running your heater? What did you see the last time you did it, if you did it? You are using distilled water in your coolent system mix, right?