We have used DirecTV for years with a portable dish and tripod. If you only want/need SD, then
Camping World has a bunch of them. We generally see that VuQube out on the road.
If you want HD, then you're going to have to go with a Slimline Dish and a Tripod. We've been very happy with
TV4RV.com. We had all kinds of installers tell us that Dish is a better way to go for HD, that DirecTV was tough to aim, etc. In my experience couldn't have been further from the truth. Easier to set up my slimline vs. the oval.
Dishpointer.com is outstanding and has a great app if you have a smartphone.
Best of luck to you!