Saber - I pull a similar trailer (Rockwood 2604WS) with a '14 Ram that does not have factory towing mirrors. I purchased a set of clamp on mirrors (they're 1500 miles away right now). I found that the driver's side clamp on is a tremendous help in seeing what's behind the trailer as you travel. The passenger's side is less helpful because the Ram mirror is convex and shows nearly as much as the clamp on. Just my experience.
2015 Rockwood Ultra Lite 2604 WS. Rear LR, large street side slide with small wardrobe slide in BR.
2014 Ram 1500 Eco Diesel Laramie Quad Cab.