Regardless of the load capacity ratings, you will get a much better (more stable) ride from the LT tires. I suggest going with at least a D load range, possibly even an E load range.

As for the daily driver ride. When not towing inflate the tires to the suggested psi on the door sticker on your truck. I only inflate mine to 80 psi when towing. When not towing, I run 45 in front and 55 in the rear as per my owners manual.