So help me God I catch someone hit and run ANY car. Spineless bastards.
Those header panels are readily available, but they aren't cheap. I got a knock-off corner light on eBay 2 years ago and it's still holding up fine.
The silver lining here (no pun intended) is the bumper looks like only paint transfer, so that will save you.
I hope you have coverage on this. Matching silver paint is hard, therefore can be costly. By the look of the picture, you're going to need to paint the whole bumper, header panel (new one will be primed), and fender, which also means blending the hood, grille, and maybe even the other fender. If you cheese out on the paint, it's going to be obvious.
Most importantly, keep on the lookout for a white car with silver paint on it.
True story:
Shortly after I graduated high school, I was hanging out at my girlfriends house when a man came to the door looking for his daughter (they knew each other). She wasn't there, so he left and I didn't think anything of it. I drove home that night thinking that my headlights looked a little odd, but I didn't think much else of it. The next morning I go out and see that my passenger side was crumpled up from someone backing into my car. I call the police, but they can't do anything because they really have nothing to go on, so I go on the hunt. I'm straining my mind trying to think of when this would have happened, where, etc... Then I got the idea that it may have happened at my girlfriend's house, so I ask where this guy lives. I drive up to his house and his Expedition is sitting in the driveway, so I get out and go look at it. Sure enough, there is red paint on the bumper that looks just like mine, at the same height as where the damage on my car was. I pull the car around the corner and call the local PD.
They show up and I roll up to the house with them. The guy had left by the time they got there, so we are sitting there waiting. Not 10 minutes later he comes rolling up, gets out of his car, and asks what is going on. The smell of alcohol is so strong it made my eyes burn. The police promptly arrest him, cart him off to jail on a DUI and hit and run. A week later I had a check from his insurance for the damage to my car.