So what I've learned so far is; working lines = difficult dog to train, strong willed type. It sounds like It takes a calm collected trainer to train WL's.
Is there working line dogs that can be easy going, calm, not hard headed in training, yet turn the switch on when needed?
Your generalization about WLs could not be further from reality. WLs are selectively bred for high trainability. What sense would it make to breed working dogs that are hard to train?
That's not to say all WLs are created equal. Different bloodlines produce dogs with varying talents and skills. Even within a single litter, not every pup will show the same drives, hardness and biddability.
*Hardness* is a badly misunderstood term. It does not mean hard headed. It means resilient. It's a highly desirable trait in the GSD.
All of that said, WLs are not for everyone. A dog with high drive and energy needs outlets. It's kinder to place that dog in a working home. Good breeders understand the need to produce strong working dogs who have *off switches*, i.e. They can settle nicely in the house. I've got a 9 wk old Czech WL pup who is already showing the ability to chill.
You may end up happier with a WG show line dog. They have drive as well, but it's easier to find a pup with more moderate drives among the showlines. Many of these dogs have some minor flaw like a missing tooth that renders them ineligible for a top show rating. They represent an opportunity to buy a beautiful well bred dog, as they will be sold as pets.
Scour the boards for more info. If you are interested in a WL dog, get out to an IPO or SDA or other dog sport club and observe.