I can't see it being impossible, I've looked into this with a ford.
The only things I can see as being a problem is the wiring loom and fusebox, the non-ac version may differ to the ac version, and then you have to change some of the switchgear inside the car. There may be small differences with radiators and hose attachments to the body under the bonet too.
Everything else you should be able to un-bolt from a scrapped car with AC and put it straight on to your car. You may need a new aux-drive belt to power the compressor.
That said... its a lot of work, I didn't do it for that reason, you're probably best off getting a garage to do it, because it all needs to be sealed properly, I understand that the refridgerant isn't kind to skin.
HTH