Frank is the most logical choice, he was practically running the division himself when John was here, so Frank should be able to lead the troops, he been dealt the "short end of the stick", but Frank understands what it's going to take to keep this division a float. First order of business should be to quit adding expansion territories, it's been a disaster, every new territory "shit the bed", second: shore up your management team, which means having to firer one or two of your AD's who underperform, third: get on any type of GPO contracts ASAP and get new products in the sales team hands, you have some very good sales people that would love to sell products that the customers actually want!
Good Luck Frank you're going to need, because of the way John left things.