We’re unsure of the sex but we are due in [name]March[/name] with our second. We’re thinking of names for the second baby–our first is named [name]Gemma[/name] [name]Juliet[/name]. We like [name]Ruby[/name] [name]Clementine[/name] and [name]Lila[/name] ____, [name]Lucy[/name] ______, [name]Elouise[/name] (middle), and for boys–[name]Sawyer[/name], [name]Graham[/name], [name]Everett[/name] (middle), [name]Sebastian[/name] (middle). What sounds good with [name]Gemma[/name] [name]Juliet[/name]? Obviously we don’t mind matchy 
As soon as I saw the title of your post, I thought how fun it would be to use other letters that are different but have the same sound (like G/J). So this won’t address your list of current favorites at first (sorry!):
[name]Phoebe[/name] [name]Frances[/name]
[name]Jeremy[/name] [name]George[/name]
[name]Cecilia[/name] [name]Sage[/name]
[name]Camille[/name] [name]Katherine[/name]
Or you could do the opposite where it’s the same letter but different sounds:
[name]Cecily[/name] [name]Clementine[/name]
[name]Phoebe[/name] [name]Patrice[/name]
[name]Phillip[/name] [name]Paul[/name]
[name]Gwyneth[/name] [name]Georgia[/name]
oh well, on to the real question:
With big sister [name]Gemma[/name], I like [name]Lucy[/name] [name]Clementine[/name] best. For boys, I love [name]Sebastian[/name] in the middle and [name]Graham[/name] is my favorite of the ones you listed. [name]Gemma[/name] [name]Juliet[/name] and [name]Graham[/name] [name]Sebastian[/name]?