Our husky is about 13 years old and she LOVES all of my kids and is generally well behaved. I have no experience with boxers or labs, so I couldn't tell you anything about those breeds.
Do keep in mind that having a puppy is just like adding another kid into the mix, so it's a lot of work (adult dogs are work too, just in different ways). But I do believe that it is good for kids to have some kind of pet while they grow up.