I know this thread hasnt been spoken about for a week or so now, but I thought I'd add my 'two-cents'.
Im not going to put my opinion on docking/cropping, but do you really think it is necessary to import a dog as a pet? I mean, when a dog is that young is it very important that they are being socialized, trained and bonded to its family, its not going to get that in isolation waiting to come into the country? Not receiving good socialization at a young age could make the dog a liability to you and your family as this can cause SEVERE behavioural problems.
IMO a Dobermann is just as scary to burglars whether it has been docked/cropped or not. ALSO, a recent study on tv, after all the riots we've ,had stated that 30% of burglers are no-longer detered by dogs in a home. And if the police see a cropped & docks puppy in the streets, Im sure they will want to see proof/paperwork that it hasnt been done in the UK. Do you really want that hassle all the time?
Finally, how did you have a pit cross when this is a banned breed? I dont mean to judge you, but I cant help it. It sounds like you want a dog for status, rather than for love of the breed.