What would be the chances and can anyone recommend where to go to buy a 6-12 month old weimaraner.

Have you thought of rescue?  There are many very young weimaraners who find themselves in rescue through no fault of their own particularly at around this age when the "cute puppy" has worn off and the "kevin" stage is kicking in.  The Weimaraner Club of Great Britain assess all the dogs that come up for rehoming and home check prospective owners and never rehome a dog that has bitten.

The main reason for rehoming is because of relationship breakups, longer working hours or they discovered that the reality did not match up to the fantasy................

http://www.weimaranerclubofgreatbritain.org.uk/html/dogs_in_need.html

Some of the dogs currently in rescue are on these pages but by no means all.  It takes time to match up the right dog with the right owner because not all dogs are suitable for all circumstances; there are many benefits but there may of course be downsides.  Depends what exactly you are looking for and what your expectations are.

HTH