right then i have a mk4 with 2.0ltr zetec conversion and i'm running mk4 efi escort loom and ecu and it works fine and was just a straight swap, you can put mondeo ecu in but do need key and transponder reciever but you can tape these up under dash or you can buy very early mondeo which has no pats or buy aftermarket ecu.
if you use the mondeo loom it'll need splicing into you loom.
if you need anymore info just ask i've looked at all the option fot this conversion