Ram 2500 with 6.4 Hemi for 5th wheel

I have towed with a V10, 6 liter gas and the last 7 years a 6.6. the diesel does not struggle anywhere and gets 3-4 better MPG`s with a heaver weight, I bet the gas motor you want is just about perfect for flats and would do great, but down the road you might want to up grade the coach and them it wont be so much fun..