Most of my dogs with the exception of the last two which have both been Rotts, have come from the local pound. We had good luck with all. All have been great with kids, and very protective of their family. 2 great ones that stand out are Ike, a cocker, and Casey, who is spotted like a dalmation, and is I think a terrier of some kind. Not sure if I ever will pay as much for another Rott, next dog might just be a another mutt from the pound. Just look for one that appeals to you, and is not overly excited or aggressive in the cage. Those are the basics I have always used. Mutts make good pups!
Good luck! Sounds the same way we got Ike, our family cocker. We went to the shelter to look around the day they brought him in, and went back at least once everyday the next few days until he was out of quarantine. We we waiting at the door the day he was eligible to be purchased.