I can't see the pictures for some reason but I have an underslung coupler and a round bar setup. I saw some pictures in the past, maybe some of those guys commented here, of a DC setup with the trunnion bars. It was setup with the bars parallel to the frame and seemed to work perfectly.
On my trailer, without DC the WD bars have an upwards angle from the hitch towards the back of the trailer. It works but is noisy like you said. I fully intend to go with a DC trunnion setup as I have had this in the past and know it works. That would be the route I would go if I were you. You absolutley beat a properly setup DC system IMHO.