I can completely understand that. Better safe than sorry.
I think the most important thing is getting the dog from somewhere you trust which can give you good information about its past. Some rescue centres, for example, will have dogs who come from all sorts of backgrounds and are suitable for...
In fairness, most rescue centres now do in-depth assessments of any animal they rehouse. They will also know the history of whether or not the dog has successfully lived with children in the past.
Not something I would worry about -it is probably best to be careful of any dog around children...
Go to somewhere like Raystede and talk to them. Explain your situation. A lot of rescue centres have dogs which will suit various different household set ups.
They might, for example, have an older dog who is used to not having someone on hand all day every day.