In my opinion a regular dish is difficult to aim. It took us several months to get used to it and lots of frustration. I would get the cube that automatically locks on to the satellite. Ask DirecTV when they come to the house for an extra receiver that they don't hook up. They charge for each receiver. I think $6 a month? You can leave that one in the camper. If you don't want to pay the extra monthly fee, you can disconnect one receiver from home and take it with you. We found that we liked having the extra receiver. That should be all you need.
Note: once the card inside the receiver is activated and there is no power to the receiver for 30 days, the card becomes inactive and you will need to reset it. We did that online, but you can also call Directv to do it.
Some campers are not wired for satellite. The TV or Cable input in the service bay may not be the proper cable to carry the satellite signal. You may have to run the cable directly to the receiver. Some people run it through a window.