Hello and welcome to the forums! Congrats in advance! I'm curious, did you meet a parrot that made you decide you wanted one? There are so many species offering you so many choices. As GaleriaGila has mentioned, all birds are unique with personalities all their own, there's no guarantee any of them will talk, some species are more likely to talk than others. African Greys, Quakers, Amazons, Macaws top the list but all parrots have the ability to speak.
If the bar spacing is too wide it can be a danger to smaller birds. The wire gauge is important too according to the strength of the beak, some birds are avid chewers, the smaller gauge wire of a flight cage isn't strong enough for some species, just one example.
Some parrots tolerate children better than others, again there is no guarantee, with three children, I would choose a young bird, parrots adapt to new environments better at a young age. Parrots are fragile, I would be very careful with the children and with your dog.
A lot can be learned about various species by reading and even more can be learned by visiting pet stores or rescue centers where you can meet a variety of birds and interact with them. I think you'll find experienced parrot people will be more than willing to help you with your decision.
