The answer to judge shopping isn't making the president a king.
Do you mean to say we can have a functional judiciary with only a supreme Court to rule on everything?
"The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behaviour, and shall, at stated Times, receive for their Services, a Compensation, which shall not be diminished during their Continuance in Office."