Large breed dogs and kids

My husband wants to get a dog but a medium to large breed. He has his heart set on a Doberman or Belgian Malinouis but I’m a little nervous as we have a 3 year old and a 10 year old not to mention we also live in a small condo with a tiny yard. I personally would rather get a smaller pup such as a bull dog, beagle, or Bichon Shitzu but he’s not going for it. I told him if we got a big dog I’d like a golden retriever or a lab as I know most are pretty good with kids but my husbands family breeds and trains big dogs so he’s grown up with them all his life which is why he’s more inclined to the “intimidating” ones. When I say train I mean they train them in obedience and as guard dogs or protective dogs for the police and what not. I also wanted to adopt but my husband is all set on buying a puppy from a registered breeder as he says then you know your getting a healthy pup that will live hopefully a long time. But it’s also hard to find adoptable dogs that are good with kids. I’ve been checking the humane society and adoption sites daily.