I would pronounce
Amias as Ah-my-as as well. I think it is absolutely gorgeous and I think it would match most of the names that you like such as
Caspian,
Aubrey,
Darcy, and
Boyd. It also sounds great with
Maxim!
For a sibset I would go with:
Caspian,
Georgina,
Amias and
Rowena
WDYT?