New tow vehicle...6.4 hemi or Diesel?

My 2 cents says Cummins for sure! Regarding 2500 or not you simply MUST do the math, unless the truck you are considering buying a the absolute base model I don’t think you can even think about pulling a 12K trailer and be in spec. Payload or RAWR is going to be exceeded almost for sure. Many well tell you they don’t mind being over design specs “it pulls just fine”. My question is always, does it stop just fine in an a emergency? I personally am pulling my 12K fifth wheel with 2019 Ram 3500 longbed precisely for that reason. Good luck!