Eeeek ! For a new compressor fully installed including parts and labour, in my experience if one can get it done from under 1k thats not bad going.
Trying various ford wreckers may be an option to find the parts you're after, or maybe these places that do exchange service may be worth a go (although I have no idea who these companies are). May be worth putting up a wanted advert on this site -
http://www.autoparts.com.au/viewparts.asp - I've found this to be a quick response resource for finding parts, and you don't need to be a member of the site either.
At the end of the day I guess it all depends how long you plan on keeping the car for. Personally, my HC series mondeo is starting to feel quite a tired little car despite it being well looked after, so I suspect I won't be keeping mine for too much longer.