I say:Ava, AH-vah Eva, AY-vah (AY like ape) Iva, EE-vah, but that's knowing its origin. I might be tempted to go with EYE-vah otherwise since it's so visually similar to Ivy EYE-vee. I very seriously dislike Eva said EE-va. I'm from the US, as a matter of interest.