The only big issue your going to run into with Dodge is the transmission. The Cummins is by far one of the best diesel engines you can get. The problem is the tranny can't handle the power.
With that said, 2500HD Duramax is the way to go otherwise. Allison Transmission and plenty of power. I've got two in my fleet (Just purchased my second one for $16,800 today). We have alot of hills around here and it handles it like a boss. You would never know a trailer was even attached, and we pull a 16ft enclosed daily.