You might find that an older dog fits very nicely in your home. They tend to be house trained for the most part, and typically get along well unless there are problems from former homes. I personally would not recommend some of the very active herding breeds though. My dog was rehomed at least 4 times before I got him and I took him to save his life. He is doing well with training, but it has not been easy. He can be reactive and I have to be careful about situations I put him in. The tradeoff is that he is a joy to work with because he is exceptionally intelligent, an border collie/Australian cattle dog mix.