I love both
Ciaran and
Cillian on their own, but they are way too similar IMO, unless you're going for an extremely matchy-matchy sibset.
Even if spelled
Killian, they still sound too similar. You'd be better off just using
Ciaran and
Cillian, because
Ciaran and
Killian clash in style. (
Killian is anglicized while
Ciaran isn't, so they don't even seem like a sibset.)
I much prefer
Josephine to
Josepha. It's not that bad though.
we all share the same sky - the maine