Gaz. I am fitting an MT75 in to mine. I got my gearbox from GBS, they myst have finaly run out of supply of donor cars they once had. You can get a fully refurbished MT75 for £350 from e-bay. it of a long linke, but here it is.
http://www.ebay.co.uk/itm/Sierra-Granada-Capri-Kit-Robin-Hood-Locost-MT75-Gearbox-/110742804057?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19c8c91659#ht_1926wt_1398
I am not sure if a type 9 gearbox mates to the Zetec or not, I suspect it will.