Sorry I missed this thread. I would like to comment as a veterinarian if I may.
If the "purebred" thing is not important to you, then may I suggest a mixed breed dog that closely resembles the type of dog you would like (I am guessing that is black lab). Few reasons for this:
1. hybrid vigor - mixed breed dogs tend to have less genetic problems than purebreds (eg. hip dysplasia is a problem in Labs)
2. Less expensive to purchase (even free)
3. Your local shelter will be able to show you several examples that you can interact with before deciding. Believe it or not, that can be important.
Whatever route you go, ensure your family knows and understands the huge responsibility it is to properly look after a dog. Too often the shine wears off after a length of time and the dog gets neglected to a certain degree. That being said, a dog can become and integral and important part of any family and can teach your kids lots about sharing and responsibility.
Good luck with your hunt!
Rod
Mighty is the mongrel! :d
Both the dogs I've had have been "mongrels" and they have/had been wonderful companions and friends.
Dodge........German Shepherd/Labrador X

Jack........Australian Shepherd X
