I definitely feel you on having to come up with another boy name. We are having to name our second boy after being convinced we were having a girl. I like your biblical name theme and really love Ezra. I would petition my husband to use it myself if our last name didn't begin with the same syllable that Ezra ends in. And I very much doubt that Ezra will become that mainstream. I don't know a single one in real life. Keep working on your hubby. I think Ezra is great!
I really like the suggestion of Gideon for you! Good luck!!!