It would be easier to fabricate your own rear end by modifying the current rear IRS with a "box" in the middle of it to mount a rear diff, then fab your own "forked" lower control arms to allow half-shafts to pass through them. Then use some front coil-overs meant for a honda civic front end, with the honda lower "forks" on them from a junkyard honda. If I had a car to fab this up on and the money to do it I would already have done it. I have it mostly figured out/planned out in my head.
Uuse the jag trans, remove the output shaft and have one custom made to replace it with the proper diameter and splines for the zetec. use jag rear diff, have jag half-shafts shortened for proper track in rear, have jag driveshaft shortened to go in exhaust tunnel of focus. fab custom rear subframe/IRS to hang it all. BOOM stock-looking focus AWD. Add a powerworks or nice turbokit and you have a pretty serious sleeper
My majorly huge hand-made Focus RS replica build: http://www.focusfanatics.com/forum/showthread.php?t=289061
My RS conversion is For Sale: http://www.focusfanatics.com/forum/vehicles-sale/578185-sale-rs-mk1-conversion-2003-focus-svt.html