The extra pins are for things like running lights, blinkers, LED's and whatever else is in there.
Any of the Halogen Focus lamps will have the same plugs. The difference is how many pins are filed ... and I'm not sure where you can get pins.
If you feel ambitious, you can look through a Tyco Electronics e-catalog and you might find the correct ones. Most of the Ford connectors are in there, you just have to know what type they are, which can be very difficult.
Digi-Key is another good source for pins.
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