Purely from a strategic view, the GOP ticket needs at least one, if not two, candidates from a Great Lakes state. Scott Walker (WI) would be my first choice. Gov. John Kasich (OH) (provided he wins reelection easily this year, as he should) would be fine, as would Mike Pence (IN).
Scott Walker recently did something to knock him off my list but my failing memory can’t dig it up. It must have been gun related though.