Obviously you have no clue about UK quarantine regulations..they are very strict, but there will be some changes from January 1st 2012 making things a bit easier for dogs with the Rabies Serology Certificate (from one of the two approved UK labs)I would suggest looking into Hawaii, to get a dog. They are rabies free so importing would be easier to start with. You may not have to quarantine then. You'd have to look up your import laws and see about Hawaii as most places consider it seperate from the USA when it comes to importation laws.
Have you any previous experience with the breed? Any specific reason you wish to have a cropped/docked dobermann in UK? I might be able to point you in the right direction if you tell me more.