Michael Wilkinson reportedly talked about BvS at CCXP in Brazil.

About Aquaman:
>My inspiration for Aquaman is actually Jason Momoa, he was born to play Aquaman. And so, he has some fantastic tattoos of his own. And got my mind thinking about how to go in a really interesting new direction for the scales that we usually see on Aquaman, so we decided to do them with tattoos and with some cool armor.
He also said that he starts in a way but develops a new look.

About Batman:
>(...)he's been fighting crime for twenty years on the big bad streets of Gotham and so his costume is shredded and it's ripped and it's torn. It's distressed, it's got bullet holes in it. We wanted to say, 'this Batman doesn't really need gadgets or armor,' his intimidating strength is his real power.

There's more, including about the supposed nightmare.