Hiring: Questions for a second interview??

Help with suggestions for a second interview?

We are inviting 2 program manager (health care) candidates in for a second series of interviews. The first has great credentials and strong, relevant industry experience. Poised and mature, this candidate has worked mostly in larger organizations, and mostly as a contractor. What we are really trying to probe with this candidate is do they have the ‘fire in the belly’ at this point in their career to do what it takes to herd cats in a startup environment?
The second candidate has worked in a startup before, as well as larger companies. While seeming to possess sufficient business savvy, tact, and enthusiasm, the second does not have the industry credentials but does have an advanced degree and seems to be more than willing and capable of learning the required tech skills. Some have expressed concern that the additional time presumed necessary to get this person up to speed would be difficult to invest given looming deadlines.
What I am asking of this esteemed group is for some suggestions for probing these areas of concern and any past experiences you might think relevant. Thank you for taking the time to respond.