I would advise against getting one at christmas. It is a stressful time of the year, with many hazards for young puppies. Not only decorations, and people coming and going, but also rich non-doggy foods that will upset a pups system easily. Not tomention most people are really busy that time of year, and with a American Bulldog pup, you will want to bond with it as much as possible to get the dog to be the dog you want(I.E> protective but calm, good with kids etc)
Wolfy