You're not going to find that bumper for sale. It is fully customized. Axle Tech is a General Dynamics company that builds military and commercial grade axles. They also happen to build portal axles and portal axle outers, which are used on the Hi9 axles under that rig. Axle Tech does not make bumpers or really anything else for offroad applications.
And jherrington, did you try to search for that bumper? Because it wasn't easy to find any information on it. The company logo is completely different and Axle Tech does not cater to offroading. Also, the actual Petersen's build on that rig was very difficult to find with just a picture to work off of. No bumper info is listed on the build so I had to connect the dots.