I feel your pain, if you check my posts I have one detailing our attempts at finding a dog. We had similar experiences, but it all turned out perfectly for us, and I'm sure you will find a great dog as well. I was looking for an older dog, but we ended up with a puppy. We got him through a rescue here, and he is fantastic. I do think the puppy thing is lots of work, but it is all worth it. We have a lab mix (I know you don't like labs), the rescue says he is a labradoodle, but he looks like a lab golden mix. My point is to let you know about his protective qualities. He is exactly what you are describing! The first night when I picked him up from a rescue it was hours away, so by the time I got him home all the kids were asleep. When our 5 year old woke up in the night to come to our room he barked loud and low, but wasn't aggressive. He then became accustomed to the correct noises in our house and never barks at them. 3 weeks later my BIL came to stay, and he and his wife went out to a concert, coming back after midnight (sadly, not something that ever happens around here
). The puppy bolted off of our bed and barked in a scary manner. We told him it was OK, and he saw it was them, but he was definitely protecting us or his house while we slept. Other than that, since he is a lab mix he is just friendly, and not at all aggressive. Our old schnauzer also barks if someone comes to the door, although I don't think she would notice everything as well as the lab mix. I definitely think this puppy will alert us to anything unusual, and probably scare someone off. I doubt he would actually protect us, but as you said in an earlier post it would give you time to get your gun. I think you don't necessarily need to be looking for a guard dog, as I think this is a common trait in many dogs.