The only real difference in round vs trunion is ground clearence on the bars. Round bars come out of the bottom of the hitch head and tend to drag on lower vehicles.
Get the 1000 pound toungue weight version of either and you will be fine. You should not need sway protection unless you plan on towing a travel trailer someday with the same WD hitch.
Make sure to order the correct draw bar so you are towing level, some trucks require a drop some a rise, just make sure yout trailer is level when hitched. 18" is the general rule of thumb to the top of the ball. Follow the directions on setting up the dist. bars when hooking up and you will be a happy tower.