Aries: Not such a fan, just too specifically a zodiac sign in my mind. Perhaps in the middle spot if you really like it that much.
Sawyer: Not such a fan either. It is a bit trendy. But beyond that, it just feels a bit 'rough' to me.
Brennan: I'm in the middle about this name, leaning towards liking it a bit. I think I prefer names that start with Bran to Bren (I think the nn Bran would be cool).
August: I like this name quite a bit. And I'm liking more the more I hear it. I think I prefer some of the longer versions (Augustine, etc), but my appreciation of August on it's own has been continually rising.