Ford Nav units

I am wondering if anybody has ever, or knows of wether or not this can be done. I want to find a ford factory nav unit from a similar year ford, (03) and put it in my windstar. I know you can get aftermarket units, but I want to have a factory look and fit to it. So my questions are as follows

1. Will they fit?
2. What years or vehicle models can i pull from?
3. I know i will need the gps antenna but will the factory harness from my radio still plug into the nav unit, I have the 6 disc changer with premium sound.

Any thoughts or ideas.

Thanks

anybody?

Best Single DIN Nav/DVD Head Unit?

No, I want to put a Ford factory nav unit in, and I am looking for info on what years and from which models i can pull from. So far I have found mostly 03 expeditions that had a nav unit, i just can't figure out if they are the same size as the factory unit i have now which is the in dash 6disc changer.

Thanks