ST170 disks (Ebay) , Mondeo MK3 carriers and calipers (mondeospares.co.uk)

You just need to take the holes on the hubs out to 12mm to accept the carrier bolts.

PICS:
240mm standard MK4 Fiesta 1.3 in 15" alloy



300mm setup in 15" alloy - it wont turn freely, caliper will need a trim



300mm setup in 16" alloy - fits fine!



Results may vary! the 15" alloy is a Mondeo Ghia item...
I have chopped up the alloy, to allow me to trim the calipers to the correct size...

Bonus:
ST170 rear brake assembly in 15" alloy