Well, for one it would be cheaper and less a PITA if you just spent your money on a engine rebuild and an addition of a turbo to the Zetec then to swap it out with the Duratec. Here are a few reasons why:
1)Changing most mounts.
2)Total redo of computer
3)Tight spaces
4)cost
5)from what i hear duratec is not as reliable an engine(correct me if im wrong)
I hope i help in a little way, i know there is a lot more to discuss, but i dont have the time to spew out everything.
