Look at N-Fab, I know a while back they were making a set of sliders that went wheel to wheel and tucked up pretty nice to the body. But again, those also mounted to the body and not the frame. Keep guys have and body mounted rocker protection for years, and it doesn't seem to bother those guys. I know it's a huge difference between a 4K pound jeep and an 8K pound+ full size truck, but the rockers on our trucks are a lot stronger than you'd think. Like I said, I've used my sliders a few times and have had great results.
I've been trying to post a pic, but photobucket is being a PITA.