I disagree with rescue dogs being the best if you want anything specific, there are no 100% guarantees but you can minimise the chance of failure
with rescue dogs nobody really knows how they will behave specially when they have been kept in a kennel and not fostered. Not to mention large majority have some sort of behaviour issue, that can sometimes only appear after they settle in with you
with a wellbred dog the breeder should know their lines and the dogs they have bred. So they should have a good idea of the temperament and health that their puppies have. If all of their dogs in their line get along with other dogs there is a high chance the puppy if raised correctly will as well
rescuing dogs is great but only for the right people who don’t
have anything really specific in mind and can handle aggression, resource guarding, reactivity and nervousness
getting a rescue that has been fostered rather then kept in a kennel can give you a better idea of how they will behave but still not as well as a wellbred puppy
there are also awful rescues like there are awful breeders
