You may want to have a bumper custom built. A setup that replaces the stock bumper with a heavy gauge steel unit would be a good start and build from there with thick wall tubing. Most cosmetic brush guards are weak because they are only as strong as their mounts to the front bumper, which can bend and warp when put under heavy stress. Also these cheaper bolt-on brush guards are not built with the highest quality steel.
I attached a couple pictures, maybe you can see what I'm talking about. The one I have is fine for looks, and will hold up to brush, but I wouldn't trust it against anything larger than a 1" tree. It mounts using the bottom bumper bolts and two bolts drilled through the upper metal of the bumper. It's not very thick gauge steel, and the headlight guards are only as strong as the two "Grade ?" bolts that hold each of them to the uprights. Theoretically with a welder this whole setup could be reinforced, adding stronger tabs and welding the headlight grills to the uprights, and reinforcing the stock bumper, but at that point it might be better just to fab a whole new bumper from scratch.
