Go Rhino Wheel to Wheel Step Bars
I have these on my Quad Cab, short box, 4x4. I wouldn't say they're the best, but they are one of the best additions I've made to the truck. In terms of something that benefits you every time you use the truck, it's a wise accessory.
The top of my bed rail is 4'10"; I'm 6' tall. For climbing in and out of the bed or just retrieving gear, the step in front of the rear wheel is great!
I don't think I know what you mean by 2-piece design though? My bars are 1-piece with a couple of brackets and braces per side. I didn't think the mounting arrangement was very well engineered, but they've held up perfectly well for nearly 2 years now. My only real gripe is the plastic step pads don't all fit flush, so debris and a wayward sandal can get caught between the pad and the bar. This is more of a potential problem, really doesn't happen much.