A couple of the retractable awning manufacturers area also in the home awing business, so that's what you might be buying in any case.
I think an awning designed for installation on a house might be more cost effective, and probably more suitable. There are some compromises in getting the weight of an awning mechanism down for use on a RV. My retractable awning at home was built more substantially than any power awning I've seen on an RV, sturdy enough to leave out even during thunderstorms. It was not power, however, a crank mechanism to roll it up proved adequate.