OEM is my choice, but not the 1500. The front will not work on you Sport bumper. You need the 2500/ 3500 take offs.
Here are some pictures of the OEM 2500 fender flares. I know one of your concerns was rust hiding behind the flares. While that could be a problem. I don't think it really is.
I'm not sure how many miles are on the Copperhead Pearl truck in that photo but it looks identical right now and those fender flares have been on since it was new. I have zero rust issues. The black RAM has around 125,000 mi in that photo and has spent its whole life outside in the Detroit Michigan area. When I bought it I did undercoat and spray inside all the panels with fluid film. The Copperhead Pearl RAM has been sprayed with fluid film as well. The black one did have some rust on the rear bed fender that is now under the fender flare on the passenger side. However before putting the thunder flare on. I sanded All the way down to mostly clean metal. There was one spot that was a hole about the size of a quarter. Once completely cleaned I use POR15 to paint the area. Then everything was heavily sprayed with fluid film. The rust has not growing any. The truck still spends his life outside. The Copperhead Pearl truck is a daily driver but is in a heated garage every night went home. I snowmobile in the winter I put lots of miles on driving through Michigan and through Wisconsin in the winter.
Just for the heck of it I figured I'd show this 98 F-150 as well. The pictures from 2013 and the truck had just under 200,000 miles. The only rust on that truck was underneath the extended cab on the driver side and a little bit on the passenger side. The bed was plastic like a Saturn and honestly I wish they would have kept making that style. Underneath though some of the bed supports were not looking the best.
My point is those are all OEM fender flares and had zero issue with paint rub or rust.
