I agree with Devan, I think Ava Nicole is really cute!
I've also always liked my nieces unique middle name which is Rae. Short and sweet and reminds me of sunshine everytime I hear it.
I kinda like Sophie Marie... maybe. Or Sophie Leigh/Lee. Or Sophie Rose...I also like Grace, because it's my grandma's name.
Kyle Jon & Kyle James are the ones that I've thought of so far that I like.
I also agree that you could search through your family trees and see if there is a name or middle name of a relative that you really like. It's kind of an honor to them or their living relatives that you chose the name.
Good-Luck and be sure to keep us updated as you narrow down your search.