I would have...
Grey Foster (#978 & #937)
&
Willa Pearl (#690 & #676)
Jacob John (#3 & #27)
&
Serenity Maria (#53 & #112)
Aw, I have my "middle name only" names on my long list too and it ruins everything. Without them the combos would be
John Eli and
Maria Hazel.
http://www.babynames.com/namelist/9852886