Yeah, I would suggest looking in a rescue before buying from a breeder, especially since you just want a pet puppy. I don't know a whole lot about cockers, but it sounds like this merle color isn't very desireable by the cocker community so it probably wouldn't be a good idea to encourage those breeders looking to specialize in a color that's not allowed under registration.
Side note: I have seen a little cocker puppy out at the park recently that appeared to be a normal colored red and white(orange and white?) with blue eyes. Neat looking puppy; I hope she came from a decent recognized breeding. BUT most breeds that express blue eyes also tend to have some sort of problem. In Aussies, some of those blue-eyed merles (which is perfectly acceptable in this breed) turn out to have slightly poorer eyesight, or problems with very bright light. As a general rule, darker eyes are better health-wise than light.