I know these are not what you are looking at but give these a look if you haven't already. I put these on our rig and they are very stable and they store outside vs inside your rig. One of the reasons we chose this was when ours is in storage the other ones wouldn't have enough room to swing out without hitting the wall. The other reason is my wife didn't want to have to clean the steps all the time or have a chance that any dirt or mud from the steps to fall in our fifth wheel.
Anyway these only took maybe a half hour to install and I imagine the others aren't to difficult either. I know some people have had issues with binding on the bottom of the door with the ones you are looking at.
TorkliftDan