My friends have a motorhome with a stationary Kingdome (I don't know the exact model). There are two cables from the Kingdome to the two DirecTV receivers. They are interested in changing to at least one DVR. I'm not familiar with DirecTV products. For SD would this be an R16 or R22? I know the Kingdome won't do DirecTV HD so SD is the only option I see. I see two satellite inputs for these DVRs. Can a SWM work with a Kingdome or can they use the DVR in single tuner mode? They don't want to change the Kingdome or run more cables. What's the best way to use a Kingdome with an SD DVR?