The factory mount pictured above looks to be more of a hindrance than anything. It appears like you need to remove the bikes to access the camper door, plus, it looks like it would offset the bikes way out to the right of the camper. Best guess would be that the tires would stick out at least 2' to the right of the camper making for a wide load and I'm sure I'd be taking out my fair share of roadsigns.
5444- based upon this site and others I've snooped about, the best racks seem to be the hitch mounted, swing armed style. If a guy got inventive, I'm sure you could somehow mount up a storage rack or gas can holder of sorts to the swing arm