If you go to www.champdogs.co.uk and click on Guided search, then Pastoral Group, then Hungarian Pulis, then Breeders, this will give you a list of breeders. If you look at Rockisland Hungarian Pulis, and go to their website they have some good photos.
Please remember though that their coats take up to 5 years to grow and take a lot of looking after, and underneath all that they are a herding breed, can be quite noisy, and are very agile, and need to be kept occupied. A responsible breeder would not let you have one just because you liked the look of the coat!