Man, that sucks

I hate people who have no respect for other people's cars. It's such a cowardly, shitty thing to have happen. If I wasn't still using my tails, I'd send it to you (but I don't have my SRT rear bumper to go with the 3d tails I have)
As far as replacing the light, you have plenty of options. If you want to go new (factory) the part # for the left (drivers side) is 5288527AM...MSRP $85.35. I think there is some used ones for sale here somewhere. And you can always go aftermarket as well.
No matter how you go, you have to replace the lamp. You can't get just the lens.
Sorry to hear about your hit and run. Good luck fixing her man
