Who should undertake that journey with Bale? I'd love to see him running around with Steve Zahn again, but that would likely be too similar to their pairing in Rescue Dawn. As for directors, Pajiba notes that the IMDb still lists Sergey Bodrov (Mongol) as being at the helm, while I wonder why after all this time Snyder doesn't just take the gig, as it seemed he wanted to back in '07. If I weren't so against documentarians migrating to fiction, I'd suggest Restrepo's Tim Hetherington and Sebastian Junger. If there's anyone who can make an intense film set in war-torn Afghanistan it's them -- though I hope they go on to another first-hand journalistic film project instead.
Of course, without full awareness of the story and tone of The Last Photograph it's hard to make any recommendations. At the moment, for all I know this is like the upcoming Nicholas Sparks adaptation The Lucky One, which centers around a soldier obsessed with a photograph he finds in the dirt in Iraq. I think Bale is kinda past the romantic destiny role, though. Actually, I don't think he's fit for any part involving a romance. So who knows what's in that photograph, but I'm at least up for another movie putting the actor in a rough survival situation, whether it involves dragons, robots, the Pathet Lao or, now possibly, the Taliban.