From that list, Evero is my favorite candidate based on resume.
After him, I also like Leonhard and Gray.
I find Joe Barry to be intriguing. He flamed out as the DC in Washington, but that may have been a no win situation. Since that time he's worked under Wade Phillips and Brandon Staley. So I'm interested.
Very similarly, I think Matt Burke is a really intriguing guy. His biggest influences have been Jim Schwartz and Marvin Lewis. And while he's most recently a DL coach, his background is mainly in LB's, which is the position coach area that produces the most good coordinators
The rest, I don't know how to feel about. Harris has one year under Rivera, which is nice, but otherwise I don't see anything interesting in his background. Ryan Nielsen has basically always been a DL guy; that doesn't mean he couldn't succeed, but DL Coach > good DC is a rare transition. And you could say the same for Kiffin.