If you do consider the Ram trucks I would go for the new 6.4l Hemi. More power is nice but it actually gets better mileage than the smaller, less powerful 5.7, because it has cylinder deactivation. It'll never happen while towing but will save you the rest of the time.
Something else to consider is the same truck with the 6.4 has much more payload than the 5.7. My crew cab Laramie is only 2300lbs while the same truck with a 6.4 is 3100lbs! I didn't realize this when I bought and even now nobody seems to know why the big difference.