Anna is classic, timeless and flexible with use in multiple countries.
Annie is cute in a "Little Orphan
Annie" winsome way, but it is definitely nicknamey and youthful. If I wanted to use
Annie, I would probably use
Anne as the full name.
Since
Anna is fairly common and well known, I would go with a longer and more unusual middle name.
Anna BoudicaAnna ZoraidaAnna KeturahAnna WalburgaAnna ConsueloAnna Hodierna
Anna Tisiphone