It could help if you would post your wheel base so someone doesn't have to look it up for themselves.
That said, I believe, as long as you stay within your payload capacity, you should not have an issue with sway, provided you have a good weight distribution hitch with sway control.
Focus on payload, as that is the number you will likely reach before any other number. And since you haven't bought the truck yet, make sure what you do buy has LT tires (vice P rated passenger tires).
Ram 1500's have one of the lower payload capacities of the 1/2 ton family. Especially the Laramie edition, which is the higher end. Those extra options reduce payload. If I were going with a half ton, I'd be looking probably at Ford or GM (Chevy/GMC).
Mike