I would like some advice on whether I should choose a white or black and tan German Shepherd.
What is the differences between the white one and are there any pros and cons. Are white GSDs more docile?
Color really doesn't matter. There are some people that are trying to get white shepherds into their own breed, but for now, they are still a GSD, no matter the color of their fur. There really shouldn't be any major differences, other than differences between lines, like show vs. work. They are still the same breed. The better question is how to find a good breeder, and if they happen to have white dogs, great!
From what I have read and heard, it is much harder to find a good white GSD breeder. They certainly exist, but quite a few of them are more worried about coat color than good temperament or health testing. If you do decide that you only want a white German shepherd, be very careful. There are some members here that have white dogs and may be able to point you in the direction of a good breeder.
What I would look at is your activity level and what you want to do with the dog whether it is black and tan or white. Figure out what you are looking for and find a breeder that breeds for that. And depending on the litter the breeder should be able to pair you up with a puppy that fits what you want. I wouldn't limit myself to color just think if you picked a puppy that was solid white and they weren't what you were looking for but a sable puppy who would have been perfect for you was passed up because you got stuck on the color and it works both ways I'm not picking on the white GSDs. I had a white GSD I got from a byb who was breeding for the silver and blacks and I was lucky. He had the best temperment and he was just amazing. I had a few byb GSDs and finally decided to look at temperment and nerves.
I have a white shepherd and a black and red (wgsl), and they are both wonderful. My white shepherd seems to be softer than other GSDs I've had in the past. A strong verbal correction makes him put his ears back and stop in his tracks. Like all shepherds, he needs structure, training, boundaries, and clear leadership, but I don't think he would do well with heavy handed training methods (not that any dog does). I'm not saying that all white shepherds have that temperament, but it's a difference I've noticed in this one.
Be careful of backyard breeders when looking for a white--if you go that route. I would look for a breeder who shows, titles or works their dogs in something. This helps to ensure that the puppies will have good temperments. Though they are disqualified by the AKC, whites can be shown in UKC shows. Of course look for someone who also health tests their dogs. The parent's hips and elbows should be cleared, and the DM status known.
I love my white dog, he is super easy to live with.
I do believe there are not a lot of reputable breeders of white dogs in the US. But it's really just a shrunk down version if the regular gsd situation, there are TONS of sub par breeders of German shepherds... Research your breeder thoroughly. If you aren't going to bother doing that then give your money to a reputable rescue and adopt something instead.
I would go more off of breeding and individual personality vs just the color. I've had sables and now a white shepherd. True my white shepherd does seem to especially be fond of people, kids, animals and is very gentle... but he still has very good drives and a strong desire to work.
White German Shepherds are the same genetically as any other coloring. If you are interesting in a White Shepherd, I know a breeder who does OFA testing (Hips and Elbows) on all her dogs. This is something you need to be careful of, as someone else said. Some breeders breed only for color. This one is definitely ethical and does all the testing. As for temperment, that depends more on the lineage and the individual puppy than it does on the color so pick a color you love then find a puppy that fits your lifestyle and family in that color.
(The breeder I mentioned is in Northern California. I have purchased pups from her before and have always been really happy with them.)