Its not going to be cheep to scource one of them in OZ. personally i would go with a 4X4 floorpan from a readily availible car here in OZ and then parts are a breeze to scource. If it were me i would graft a, dare i say it? Subaru STi or WRX floorpan, onto the escort, i have seen somewhere a thread that someone is doing this, will try and find it for you.
But if your mind is set on a ford 4X4 floorpan then try looking at trade me in new Zealand lots of interesting bits over there.