My black lab, very everybody friendly. Not sure if he'd protect or not, sure acts like it, but has never backed it up. More of a wal mart greeter. Yellow lab, will stick like glue to me, or at least she did, getting older now, but she still wants to, but she is a follower, always behind when walking. My pit, or pit mix, came to me last October. She had been set out, looked like skin draped over a skeleton. She is another stick of glue. Yes I do think she would protect me if she needed to. I can not leave her inside due to her separation anxiety.While I am here, she mostly stays inside, with zero issues. She stays at home when I leave, at least she's always home and waiting when I return, no matter an hour or five. I leave and tell her to watch after the place. My packages have however stopped being put on my porch, they end up on the hood of what I didn't drive, or on the bed(if it's my truck I left) So, I don't think she allows anyone to come that close to my home. But, when I am here, she goes out to greet anyone who comes. Yet, when someone pulls into the neighbors yard, she acts like she wants to eat them! That is, untill I tell her to come back. She acts very good to commands and very quickly.
I do recommend shelter animals, for the same reasons everyone else has mentioned, but in your case, I would recommend a pup. And, like was mentioned, let the dog sleep with the kids, let the kids feed them, make that bond as strong as you can, and I think they'd always be protected, till the death. The pits have short legs, but lots of stamina, from a pup, I think they'd be all you want them to be. The same in my experience or rather my observations can be said about the GSD. Either would do all you desire.
