Bong congrats!
I would go (in order) Miles, Ellis, Ollie, or Finn - as gentle, causal and relaxed but also trim & tailored, like your other two.
I don’t like the repeat S in Spencer and don’t really see it matching. Oakley, I agree is a little too trendy/ stylised, and pretty intense for what should be a low key, nature name
Others: Jules, Theo, Marlo, Kai, Jude, Leo, Walter.