Who Plays Jack and Jill in the Cycler Movie?

A while back, I hinted at a movie deal for Cycler. I've been holding off announcing it officially because, well, these things take time to iron out. Film contracts are long and tediously-detailed things.I'm happy to report now that I have optioned the film rights to producer, Don Murphy. Don has a distinguished track record, which includes Natural Born Killers, Permanent Midnight and the Transformers movies. Even more importantly, he completely gets Cycler and wants to bring it to cinematic life in a way that's faithful to the book.Of course, the above will be made much easier given the fact that he's using a screenplay I wrote. It's not often that novelists write their own screenplays. Screenwriting and novel-writing are very different in a lot of ways. But I actually began my career as a screenwriter, and Cycler began its life as a screenplay. So, in a way, this movie deal completes the circle.The funny thing about adapting Cycler the novel into Cycler the screenplay was that I had to recall all the things I had purposely suppressed when I made the transition from screenwriter to novelist. To write novels, you have to paint the scene in great detail and place the story in the reader's head. To write screenplays, you have to keep things sparse and leave room for the director. I had worked really hard to avoid writing novels that were too "cinematic." As a result, my first draft of the Cycler screenplay was too "novelistic." It was full of pointless voice over and excessive detail. But once I got back into the swing of things as a screenwriter, it all came back to me. And I'm really happy with the way it turned out.Now, the big question is: how on earth do we cast it? Do we cast one actor to play both Jack and Jill? Or do we cast two actors who resemble each other enough to pull it off?I know which way I'm leaning. What do you think?