I will go a bit against the grain and tell you to look at some of the larger, lazier breeds.
The Leonberger and Newfoundland immediately come to mind. They are large and imposing enough to make anyone think twice about messing with your daughter, but aren't nearly as energetic and driven as many of the working and herding breeds. They are also fairly gentle and not as likely to view your cats as chew toys.
Leonberger
Newfoundland
The thing to remember is that no dog is going to be perfect right off the bat. They need to be trained to know what is and is not acceptable behavior. They will be energetic and destructive for the first 2 years. Also, 8 hours at home alone is too much for any puppy. If that is to be the normal for the dog, I suggest dog daycare or dog walker. If you can't do something like that, you need to make plans for how the puppy will be able to take potty breaks during the day, because until a puppy is about a year old, it won't physically capable of holding it for that long.