I just replaced our 7 year old Kingdome receiver with a Winegard Travler earlier this month (roof mount). Very straightforward instructions and it worked just as advertised for the short 12 day trip we've taken so far. No dropped signal even in extremely hard rain.
You will need to decide which carrier to go with before you buy your antenna as the Dish and Direct antennas are different. We now take our Hopper and Joey from home, which allows each tv to watch it's own channel AND has a huge DVR (I have 262 shows recorded and my hard drive is 13% full) for recording shows and watching them when you want. The Kingdome required a special receiver and both tv's had to watch the same channel and no DVR.
We bought our Travler from PPL motorhomes because of the best price. HOWEVER, they do not offer the "duo node" which is needed for a two tv installation. PPL's rep didn't even know what it was, much less have one in stock when I provided the part number. Fortunately they are easily available online.
If you hadn't thought of it yet, it may be beneficial to change your home tv carrier to whichever satellite carrier you decide on. Then you'll have the exact same channels on the road as at home. You can use the same recievers in both places, you don't run into having to pay for a month of service for just the weekend you're camping, etc. We travel in the MH 6 months each year and with Dish we can change the local channels (service address) whenever we get outside the spot beam. If you live in WA, for example and are vacationing in AZ, you will get a message that you are outside the viewing area when you try to tune in the local ABC, NBC etc channels. By changing the service address you will get the local ABC, NBC etc channels in AZ.
Ken