I recommend that you start training thechildren before you get a dog. Small kids and pups can get into trouble as pups see them as equals. Here's a link to a good article. You can get a quality family gun dog going through reputable breeders and breed rescue. Several years ago we homed 17 dogs when our friend, mentor and breeder of one (now 3 of our dogs) passed suddenly. You might look at a "started dog" this dog has had some training and just may not make it as a trial dog or for what the trainer/breeder may want. My last gun dog was a field trial washout. Check with the parent club of each breed (national club to locate a local breeder). Always buy a gun dog from field lines.
http://www.akc.org/pdfs/PBSAF2.pdf
http://www.akc.org/public_education/responsible_dog_owner.cfm#getready