I'd suggest you to attend dog shows. There you can meet a lot of breeders and owners of the breed. These people release puppies only after they are 1 month old and they can let you have a look at their parents. I'm buying a puppy in june. I attended IIPTF in my city, delhi, where I met a lot of good breeders of Lab, Rot, GSD, etc. I could meet breeders of rare breeds like Siberian Husky, Weimaraners, Bull Mastiff. I'm also against buying puppies from pet stores so I tried to catch reputable breeders. I have no. of few but none for Great Dane as it's not what I intend to own.
We had a great dane dog show today in Delhi. I'd suggest you to attend dog showns and try to get hold of some reputable breeder. They might not have puppy right at that time but when they have any they can let you know. The patience can play a crucial role.