Personally, I'd go with Johan. I just feel like I a have a slightly better chance of surviving that minute wit him, as Johan is far more stable than Bateman; he doesn't snap into a bloodthirsty rage like the latter does. Sure, he could break my mind with one conversation, but it's a hard pick, and while Johan is a terrifying genius who, in general, could certainly do worse things than Bateman, Bateman is a total psycho could snap and torture you to death at any second.
TLDR; I feel like I have marginally better odds in a room with Johan for a minute than with Bateman, due to the latter's "utter insanity".