getting parts is not that bad, as said, most are available from " other sources " or there's always EBay !! there not the cheapest of parts but there out there, with trim and panels being the hardest to find.
ford still do a fair bit really, i got skirt clips and an alternator just last week for just over £100
things that are shared with other models you can get from motor factors / halfords, ( CV boots / sierra XR4X4 , brakes are that of some sierra / Granada models ( although you want modded parts for that !! )) doors are that of all MK5`s
don't worry about it, i would not let it put you off !!!