This question really speaks to me because I'm in a similar situation. When we got our first dog two years ago, we did it "right" and got a rescue. After a long search, and failing to find any suitable dogs in shelters, we adopted a dog from an excellent breed-specific rescue. They did a great job and answered all of our questions, but we ended up with a dog with much more sever behavioral issues than we anticipated, including fear-aggression. After tons of training, she's made huge progress, and entirely stopped resource guarding and reactively barking at people. But she still has body handling issues and occasionally snaps at me for trying to take her leash or collar off. She'll tolerate my husband's hands near her head, but not anyone else's. The rescue was surprised to hear of her intense fear of people's hands, since she apparently did not show this with her foster parent. (Somehow, she is excellent with dogs, even though the rescue said she wouldn't be.)
I want another dog, and I really don't want a second dog with behavioral issues -- what to do? I know most rescue dogs are not as difficult as mine, but still, almost all of the Border Collies, Border Collie mixes, Aussie mixes, and Kelpie mixes in rescue near us seem to be adults with behavioral issues. No surprise -- rescues come from bad breeders and usually not the best owners. And it's still a roll of the dice whether more issues pop up post-adoption, as happened with my dog. On top of all that, rescue is very competitive around here. My dog's foster parent rejected literally dozens of applications for my dog before approving ours. We are a sort of sports home, so rescuing a mystery mutt isn't appealing.
So breeders are looking more and more tempting -- specifically a breeder with a history of producing dogs with good temperaments and who values socialization. I really like the idea in this thread of trying to buy a dog that washed out of herding. Do you all think a dog used to farm life would struggle in to a suburban environment? I.e. strange dogs walking by, screaming kids on bikes, the commotion of an agility event, house parties, etc.? How old are dogs typically when they are rehomed due to a lack of herding ability? I'd prefer to socialize a dog myself if possible, since after seeing the effects of poor socialization so starkly, I don't really trust anyone else to do it. But if I could spend a lot of time with the dog before buying it might be okay.