I pull pretty much the same trailer set up you have (5,500 dry, 8,000lbs gross) with absolutely no issues. Vacation the past 5 winters in Florida (from Ontario).
Couple weeks ago traded in my 2014 on a 2017, but both trucks have the same driveline (5.3L, 4x4, crew with 3.42 gears). The only difference is the 2017 has a standard box up from the short box.
When looking for a 1500 truck, the biggest thing you need to be mindful for is the GEAR ratio.
Stay away from 3.08s if you are going to pull anything bigger than a popup, they are only rated to pull 6,000 lbs or so.
The 3.42 gears are good for 9,100 lbs.
Good luck in your search.