I hate
Ariana. I couldn't tell you why, but I just do.
Anna is beautiful and classic, but if you want the "ah" sound, you should go with the Spanish
Ana, even though I've only seen that paired with other names (Ana-Maria, Ana-Lucia, Ana-Leticia, Ana-Uxia, etc.).
I prefer
Anna of
Julia and
Lydia, but I like them both too.
As for you sibset:
Isabel,
Nicholas,
Sofia, and either
Gabriel or
Adeline.