I think we've settled on Jackson Arnold! Arnold is a great-gpa name, Jackson is an adapted great-gpa name (originally John but goes by Jack anyway) It'll be Jack and Jackson, not necessarily one or the other.
And I can't tell you how excited I am because my husband just decided he liked my favorite! I was all prepared for a debate or disappointment.
Re: s/o name choosing...
I wanted a Jack but dh vetoed it.