If you are only going to use the TV for a few trips a year then it sounds like the vehicle will also be your daily driver. You may be happier with a gas engine then a diesel in a 1/2 ton. The emissions on a diesel can be a problem if do a lot of short trips and idling. Tow rating and large fuel tank are things to consider. When I shop for a new vehicle I set the price aside and look for the most important features I must have then, I address the price as it can be negotiated. Some 3/4 tons ride very nice. Look at them before you purchase.