do a st170 change there is a place in b'ham that will sell i every thing u need engine gearbox loom ecu shafts mounts the lot for £990 i think thay are on ebay
i would say that would be the best way
cause then u get 170bhp 6 speed and its all focus stuff so bolt in and away u go
http://cgi.ebay.co.uk/FORD-FOCUS-ST1...1%7C240%3A1318