Headlights in good shape are very very hard to come by. I tried a few years ago but you can always try the wreckers but usually they are pretty damaged. I got lucky and had some damage happen to my car and ended up getting new ones thanks to insurance. The door trim I am assuming your talking about the ones at the base of the window on the outside, I would probably stick with what Ford sells for the car. Wreckers may have them too but they may not be in the best of shape. They get coroded and stuff. Mine were really bad when I changed them. If I remember correctly the cost at the dealer was about $25 a piece.
