The breed you get matters a _lot_. Different breeds really do have different personalities, and while you can get the odd goose out, most of the breed tends to show off that personality, for better or worse.
I've heard a lot of great things about Dewlap Toulouse but have never had any, myself. The one small flock I was around was very mild-mannered, but still louder than my American Buffs and Pilgrims (just because they were chatty - none of them were really "loud"
.
Both American Buffs and Pilgrims were bred with personality taken into consideration. I'm spoiled rotten with both and lean toward liking my Pilgrims more than my Buffs. I have never been attacked by either breed - even while raiding eggs and tromping across their nesting sites.
Both breeds are more difficult to come across, but well worth the wait. If you want something that will definitely be friendly with your kids then you can't go wrong with either.
American Buffs, Pilgrims, and Dewlap Toulouse all need more help when it comes to promoting and furthering the breeds. If you do decide to get one of them I'm all for trying to talk you into getting a pair/trio (or more?
to help spread the goosey gospel and get at least a pair of geese in every barn and/or chicken pen.