do i pick heads or tails?
If this is a wt (walkthrough) question then there is a basic wt among the game downloads and I've written a more detailed wt which you can find here, third download option.
SPOILERS
But if it's just this: You should pick tails, even though the consequence of this choice hasn't revealed itself yet in the current version of the game. Why tails is better is still up for speculation.