ependydad is correct...you will require a wedge to activate the Reese Revolution but it will come equipped with one. The problem is the O.E.M wedge works for some but not all...You may have to order a custom wedge for it to work effectively, good news is they are not very expensive. Some have used the O.E.M wedge without issue, depends on the hitch.
If I were you I would seek a different hitch installer, because they obviously don't know their stuff. They should know a wedge would be used and that you would actually not have 2 moving parts causing a conflict. All that happens with the Reese Revolution is that the pivot gets pushed back approx 22 inches to pivot at the pinbox and not at the pin.
Our set up is similar to yours, not a Dodge, but a GM, but that really is of little importance. We have a 6 1/2 ft box similar to yours. We have a slider hitch but also have a Reese Revolution. We have used the trailer with both the Revolution activated and not. With it activated, quite unlikely you would ever have need for a slider hitch. Even with the Revolution not activated, I have never needed to use my slider, but it's there if ever the situation arises. I de-activated the Revolution because the O.E.M wedge was giving me grief, and I have not gotten around to finding a custom wedge. If you have not yet bought a hitch, I would just go with the standard hitch and activate the Revolution using the proper custom wedge. It will save you about $400. The instructions that we got with the Rockwood trailer about activating the Revolution were very clear and well illustrated.
2011 GMC Sierra 2500HD
2014 Rockwood 8289WS, Diamond Pkg.