RAMs are bad for rust, the Classic body style at least...I've seen some <5 years old getting rust above the rear wheels. That said, I'd bet that keeping one clean is as simple as getting it oil sprayed annually and being diligent about washing the salt off as frequently as possible. Make sure that whoever does the oil spray removes the tail lights and shoots oil all in the bedsides and down around the wheel arch.
It was only a matter of time before the RAM Classic was pulled from the market, frankly I am surprised it's run this long. 2010-2024 is a very long run, and it still looks great today. I like the interior too, well laid-out and very functional.
For the $, I'd probably take the risk on a Classic with the HEMI....Sounds like the issues with that engine are related to oil change intervals and idling. Change the oil, with high quality stuff, every 5K and don't let the truck sitting idling unnecessarily and it'll most likely be fine. The V6 is a safe choice, and a great option for someone like WP, but I'd want the V8 to have extra power for towing.