Of that list, Rubio would be the best choice, with Walker for a close second.
Well according to you, who will and/or who should Rand Paul pick, in order to be competitive?
I don't think he'll get the nomination, but if he did I think he should consider the following:
Kelly Ayotte
Deb Fischer
Bobby Jindal
Ron Johnson
John Kasich
Susana Martinez
Rob Portman
Marco Rubio
Brian Sandoval
Tim Scott
Rick Snyder
Pat Toomey
Scott Walker
Ayotte seems to have different views on foreign policy, although he she seems like an effective fit (diversity, regional balance and strength in a swing state.)
Fischer hasn't been tested on a national level, and doesn't bring much in terms of experience, but helps with diversity and arguments for conservative government.
Johnson's similar to Rand Paul (outsider elected to Senate in 2010 by Tea Party support), but he could be an amplification choice, and help in Wisconsin.
Sandoval's Pro-Choice, and likely to be running for Senate.
Toomey seems like too much of a generic conservative activist to appeal to the middle/ help the Paul campaign.
I don't know why you have all these men in the poll, Paul or whoever the GOP nominee is would be dumb not to pick a female running mate.
Of course a female pick will be interesting. But do you think Susana Martinez, McMorris Rodgers, Kristi Noem or another one would accept?
I also think that Rand Paul's VP should be someone who shares some of his views (Foreign Policy would be an important issue) but could also appeal to the center and independents.
Martinez doesn't seem interested in national office.
Noem and McMorris Rodgers are ambitious enough that they'd probably say yes. Noem considered a senate primary against a popular former Governor. McMorris-Rodgers gave the SOTU response. As legislators, both would arguably benefit with the higher profile that comes with a credible bid for national office, even if the ticket loses.