Honestly, I think it'll be Tim Griffin. Sarah Sanders is a national figure at this point, and I think Arkansas will be more in the mood for a figure who's actually associated with their state. And if Trump loses he may not have that ability to move elections anymore.
In a state like Arkansas, he could still have clout. What puzzles me is why she seems fixated on Governor and not on the Senate. I definitely have Boozman down as a possible retirement and she's clearly more interested in national, not state, politics and issues.