LOL! give up on that idea right now! Even if you can find a custom string builder who can make those you'll be driven crazy by the expense, the wait and the lack of choice of strings. There are headpieces available that have string clamps and can use any single ball string, you'll also find you can use most guitar strings too because they are long enough to reach the clamps. Even if such a headpiece is more expensive it will pay for itself in no time at all because you'll save huge amounts of money by avoiding custom strings.