I imagine a map like this one could be likely in a Clinton vs. Bush matchup:
Former Secretary ofState Hillary Clinton (D-NY)/Senator Mark Warner (D-VA): 320 Electoral Votes (52%)
Former Governor Jeb Bush (R-FL)/Senator Jeff Sessions (R-AL): 218 Electoral Votes (46%)
Others (Libertarian, Green, etc.) 0 Electoral Votes (2%)Overall, the map is pretty similar to 2012, though Hillary Clinton is able to pick up North Carolina and Arizona and Jeb Bush is able to carry Colorado and Florida. In addition, Missouri and Georgia are also very close, but in the end, Jeb Bush carries both by a small margin.
As for their running-mate choices, I imagine that Jeb Bush would go with Jeff Sessions in order to reach out to very conservative voters and those who are reluctant to support him over his stance on immigration (as Jeff Sessions is one of the foremost advocates of a tougher immigration policy and is one of the closest Senate allies of Ted Cruz) while Hillary Clinton will probably go with Mark Warner, though his small re-election margin against Ed Gillespie might end up as a lliability for the Clinton campaign.