Dish DirecTV Winegard questions

Hello, I recently purchased a 2008 motorhome that came with a winegard roof mounted satellite dish. The private owner I bought the motorhome from was the second owner of the rig and had never bothered with the satellite dish and knew nothing about it. I emailed winegard with what serial number information I could find on the dish, and they informed me it was a 2008-09 era road trip sti, an in motion capable dish. They said it would not work with Dish network service due to changes made in how Dish modulates its signals over the last few years. It would however work with DirecTV service, but only SD, not HD, and I would have to use an H24 or HR24 receiver. So, if I want to utilize this dish, I would have to sign up for DirecTV service, get the H24 receiver, and be ok with SD. My question is, is there a portable dish that works with DirecTV that I could use for HD (with appropriate receiver) for when we are at our camping destination, and just use the roof mounted in motion capable dish (since its already there) for use only when we are travelling? If this is a realistic possibility, then ditching cable at home and going all DirecTV might be worth it. I have done some searching and research, but being completely new to satellite tv, it seemed like I was finding conflicting info on whether DirecTV has a hd capable portable unit, and whether the H24 receiver would work with both the older Road Trip sti dish and a newer portable unit, or if I would need different receivers. If DirecTV has no good way of getting HD to a portable dish, then I would just forget about the older dish on the roof and get a portable Dish networks HD unit for the campground and maybe for the house too. It just seems a shame to have an in motion capable dish sitting up there on the roof, and do nothing with it.
Thanks in advance for any response, help or information