Jacob J. (Some Amish sons got their father's first initial as their middle initial. His dad was also Jacob. So he's essentially Jacob Jacob)
Great-Great Grandfathers (the ones I know)
Levi S. (Samuel)
I'll stop there, but I can go further back in some branches.
Paternal: William John
Horace (no middle name)
Cyril Aney Snybat - Aney was his mother's maiden name, but not sure where Snybat came from!
Roy Gustav. Not a big fan of Roy, but I could see maybe using Gustav.
Maternal: Robert Dennis
Paternal: Leo Howard
Harold (but everyone called him Slick- he was even listed that way in the phone book!)
Henry (his brothers were Hermann and Helmut)
Names in parentheses are birth names, changed when entering US
Maternal gf - Hymie (Chaim)
Paternal gf - Israel
DH maternal gf - Keith
DH paternal gf - Jacob William