Paul, I got the new bumper (which I have yet to install) on eBay. It was like 125 bucks shipped or so IIRC. But, it does not come with the trim. I have a Z71 which uses specific trim that you can't really get on a complete kit, it's a different color and type. Also, my bumper is in some kind of black epoxy primer since it's for the "painted" application. I haven't gotten around to it because I'll need to have it painted, so I might as well get the front one painted too, and my rear hatch, and so on...lol.
However, I think you can get the chrome ones WITH the trim. They are much more money, but if you don't feel like removing the plastics and stuff from the old one, it might be worth it to you. It is worth it to get the bare chrome metal section and move everything over to the new bumper if you have everything intact to do so. Sometimes the rear bumper brackets are rotted also, the new bumpers don't come with them but I think you can possibly get them in a kit.
The bumpers rot out from the back. The truck kicks sand and salt into the bumper, which is uncoated on the back, and it rots. The top of the bumper under the step pads also rots, because there are a bunch of little holes for the clips of the plastic to go through...salt gets up under the plastic. I've seen people step on the top of the bumper to get something and their foot go through. So, it's a good idea when receiving the new bumper to undercoat the entire back, and then everything up top that will not be seen once the cladding is installed, because it will rot again. Another reason to consider the cheaper one with no cladding included.
The aftermarket stuff is actually half decent, not thinner than factory or anything.