I do prefer it on a boy -
Augusto,
August,
Augustus - and for a girl
Augustine or
Augustina, but I wouldn't be put off by seeing just plain
August on a girl, especially with nn
Aggie, which would be super adorable.
As for combos, I like the short ones you have:
August Eve,
August Elsa.
August Rosemary and
Rosaline are nice too - I love
Rose names as fns or mns, mostly because they seem to go with any name! lol
I don't like
August Octavia / Kallista just because it seems too Romanesque imo
Some ideas:
August Nell (I love this one!)
August PearlAugust LunaAugust StellaAugust EstelleAugust AmeliaAugust GeorginaAugust OraAugust AdelaideAugust Ophelia /
Ofelia