Huntsman and Johnson is close to a toss up for me. It comes down to their abortion stances. I'm not all to familiar with Huntsman's, but I doubt I would like either of their stances. If Huntsman is more pro-life, my edge goes to him. If it's about the same, then edge Johnson.
Huntsman is more pro-life. He favors a right to life amendment (constitutional amendment banning abortion) while Johnson is pro-choice in the first trimester.
I don't like a Constitutional amendment banning anything, unless it is banning the government from doing something. I really don't agree with the approach.
Johnson being pro-choice is also bad.