The new Ram 2500 has gone to a five link coil rear suspenion which provides a great ride and good towing capacity, but I've heard it doesn't handle the load of a truck camper very well.
Agree, don't get a 2500 with the coil springs as it doesn't do well with the load of a camper. There was someone here who had a light camper and bought a 2500. After several mods he has gotten it to work but still doesn't like how it handles the camper.
The 3500 is almost the same cost and gives more capacity. Spend the extra $1k and upgrade to the 6.4L engine. Much more torque down lower RPM so you will find you can stay below 3,000 RPM most of the time. With the 5.7, you will be much higher in the RPM band as that is where the torque comes into play.
My 3500 is my daily driver and it isn't that bad once I lower the pressure in the back tires to about 40psi. Which is something you can only do in the 2500 if you don't mind the tire pressure warning notifications.
As far as trim packages, the Tradesman is the bottom line, but one step up is the SLT (hard to find on the lot) as it is about $2k more but gives the chrome package, upgraded seats (still not power), rear sliding window, heated mirrors, 110V outlet, and a few other things. Usually you will find a Big Horn package for about the same price as the SLT, but it gives a few more features that I didn't like.
Before I did any of this, I would weigh your current setup with horses on board and see how the weights stack up against your limits. It will also give you an idea where you need to be on the new truck.