Hang on, hold on, let's look at your post a little.
You have two small children at home. Are you aware that German Shepherd puppies are often called land-sharks? With two little kids, do you really want your boys to grow up fearful of your dog because of his puppy biting.
Now WGSL dogs bite too as puppies, but they can be a lot easier on little kids, and American lines can too. Some working line people are probably going to give me ****, but with two little kids, we need a lot more information before sending you off to get a little land-shark with high energy and high drive and hard, stable temperament (hopefully).
What do you REALLY want, and what do you REALLY need?
With two little kids, do you really have the time and the money to go driving hours each way every weekend to work your dog in IPO? Going to spend all day Saturday, every week doing this, and spend a good time every day working him between classes?
Do you need a dog that will bite and hold on and take down intruders? Or do you need a dog that will bark and encourage lazy thieves to pick an easier mark?
Do you want your kids to be able to play with other kids and let them in and out of your home, without first putting the dog in crate or kennel? I got nothing against training a dog for protection, if done correctly, and with the right dogs, it probably makes the dog less likely to bite in the wrong situation. But the liability you will face should your dog bite in the wrong circumstances is far greater if you are training him to bite, and to hold on. (GSDs generaly bite once or twice, and they let go, unless you train them to take the sleeve and hold on. This means that you get punctures and some bruising with a bite, as opposed to plastic surgery.)
Have you owned a dog before? Have you trained a puppy from 8 weeks before? Have you owned a herding breed? Have you owned a working/guarding breed?
You've been researching for a month. I am sorry, but there is a lot more work to be done. If you want to go with an American bred dog or GSL dog, you need to find a reputable breeder. If you are convinced that a working line dog is what you need, then you need to find someone who is producing working line dogs that will fit your situation like a glove, and be able to provide training and advice, and you may even want to think about getting an older puppy or young adult dog. You may want to wait another year or two, until your boys are a little older.
For a dog that should be in your family for 10-14 years, and a situation where you have two pre-school-age children, six months of searching and researching, and waiting for the right litter to be born is not out of line.