I like Nora, Kira (love this), Cordelia, and Hannah.
Kayla is super trendy, Kendra makes me think of the playboy bunny, and Darby I just don't like. I prefer Darcy.
Seems like you like Cs and Ks, maybe Cora, Coralie, Cleo, or maybe he'd go for Kyra or Keira over Kira since they are closer to Kayla/Kendra?
You may want to look into the list on this site that called Names Dads Prefer More Than Moms. Some pay pique his interest and determine what his naming style is.