I would go to the shelter.
Before I got my lab, I brought home a dog from the shelter. We all went to see the dog in kennels, but when we brought the dog home, he would not let my young son go near him without growling and baring his teeth, something that had not been evident at the shelter.
We persevered with him, but the dog could not be trusted around my son, so regretfully, the dog had to go back. The problem with dogs from kennels is that often no-one knows the history of an animal that has been found as a stray for example. Maybe the dog we had wanted to give a home to had been mistreated, maybe by a child, or was only happy in adult company.
Anyway, we bought a chocolate lab as they have lovely temperaments and are renowned for being good with kids. Having said that, my lab was totally bonkers :)