Don't even think about nominating someone other than a governor.
Sanford has all the same positive qualities as Bush, but is more fiscally conservative and has an even larger set of cajones (no disrespect intended, Dubya).
The only wild card really is how he'd handle the War on Terror. I think he'll be fine, however, because nothing in Sanford's resume suggests he'd be anything other than a hawk.
Plus, we should remember Bush had no foreign policy experience at all, but he put the right people in his cabinet and the rest is history. There's no reason to think Sanford won't do the same.