Ive got both the BOB and Burly trailers - toured once with the Burly and use the BOB around town. For long tours, I prefer panniers. In your case you could buy a used trailer and sell it if touring's not to your liking. You woudn't be out much money.
I would not strap your backpack on your rear rack. Instead make use of your numerous stuff sacks. Many ultralite tourers travel this way. One, or more on top of, and maybe strapped to each side of your rear rack; another strapped to your handlebars. Maybe buy or make a framefit pack.