So many great suggestions so far!
[name_f]Ida[/name_f] [name_f]Marianne[/name_f] is gorgeous! I love the idea of [name_m]Conrad[/name_m] or [name_m]Ambrose[/name_m] with [name_f]Ida[/name_f], too. As well as [name_f]Ida[/name_f] and [name_f]Cleo[/name_f].
For girls, I wonder if you might like [name_f]Sybil[/name_f], [name_f]Ottoline[/name_f], [name_f]Mabel[/name_f], [name_f]Florence[/name_f], [name_f]Leonie[/name_f], [name_m]Bess[/name_m], [name_f]Clementine[/name_f], [name_f]Marigold[/name_f], [name_f]Pearl[/name_f], [name_f]Esme[/name_f]? They have that slightly vintage, unexpected feel without being too out there.