Congratulations on your plans. If you want to start with a pup you have to be prepared to put a lot, a lot if time into training and socializing in order to get the dog you are hoping for. The first 6 months can basically be puppy time 24/7. With a young family that can be a challenge. As a trainer I have visited several families whose small kids were living on the couch to prevent the pup from biting them. They had thought that it would be fun if the puppy could grow up with the kids.
If you plan on pup, check the adult dogs if possible. I am sure the members on the forum can help you find a good breeder.
It can be done of course, I did it when our kids were little but dogs were my passion and outlet.
If you contact several good rescues who know what they are doing (not every rescue does unfortunately) and are willing to take the dog back if it doesn't work (contract!), you might find a nice adult dog that is passed all the puppy stuff.
Have fun with the planning, so exciting!
Deja, GSD, sable WL, female, born 11 / 2013
Cam, Rough Collie, sable, male, born 8/2015