Welcome.
I'm not sure why you want aftermarket headlights, they usually don't fit as well as OEM.
For OEM headlights contact Bill Jenkins at Team Ford to get a price. Make sure to tell him that you are a member of the CEG, he'll give you a good price and they'll fit correctly. His number is: 1-800-791-6436
Aftermarket headlights can be found on Ebay. Be forwarned, they usually do not fit very well.
