Well whichever breed you decide to go with I would defiantly go to the Humane Society. That's were I have gotten all the dogs that I have ever owned. It's nice because they usually have a chip in them that would be used to scan if they ever run away. You have to pay a small fee to activate it, but its well worth it. Also, they usually are up to date on their shots AND they give you a certificate for a free spray and neuter or if you decide to take it to your own vet they will give a discount off as well.
I know that's where I’ll always go to get a new dog...especially because if they have no space and they receive animals they have to put them to sleep. I know this because when I was young we went there to just look and there was a man in the parking lot with a mixed breed dog. He said that the Humane Society would put her to sleep if he left her with them because they were too full to have any more animals. I know it's sad...so just think of the puppy you could help save!