If its any help to you mate I remember an article in Fast Ford a while back where a boy fitted a Mk5 RS2000 motor in a mk2 Orion (which is the same engine bay as yours) you could possibly order it up from them? If i remember correctly it was quite straightforward to get it in. I know the zetecs are easy to put it but not quite so sure with the I4 engine.

Best of luck - get some pics up!