Used, X2 Collision in Maryville, IL. He has stuff on e-bay, but has much more in stock. Talk to Scott the owner and tell him Dr. Frank sent you. If you want it looked at before you buy, I'm close.
In regards to buying a used one, I was under the impression that the tail lights are to some degree a one time use due to the damage that occures when the screws are removed.
Lorenzo, you are correct. The Service Manual says one use only, BUT, people like ShelbyElite have proven on numerous occasions that they can be pulled and re-used. X2 Collision sells a lot of these if they have them.