Safety-wise stay within axle ratings and you aren't doing anything wrong. The GVWR is a clerical issue (despite what a bunch of well meaning folks here tell you their neighbor's hair dresser's uncle didn't go to jail for exceeding it).
If starting from scratch the 3500 does make the most sense but, more than the other 2 brands, Ram 2500 is quite a bit different than the 3500. The coils ride A LOT nicer unloaded than the leafs in the 3500.
I can't really compare towing since I've never towed with a Ram 3500 but I sure do like the way the coils on my 2500 handle better than the leaf spring trucks I have towed with. I have a set of Firestone airbags that make towing right at my payload max comfortable. Keeping in mind with the same load on my rear axle I'd be 700# over my GVWR if I had a diesel.
The GVWR fight will undoubtedly continue well beyond this thread so OP you just have to gather the facts and decide what works for you.