SPOILER ALERT: This section if full of spoilers. Enter at your own risk!
Ian Murray Jr.
My Ian Murray Jr. would be played by Joe Mazzello. I knew the moment I saw him in HBO's "The Pacific". He's perfect. Ian is tall and homely with the most beautiful, soulful brown eyes. Joe Mazzello has or can be all of the above. (I'm sorry about the "homely" thing, Joe! I think you're adorable!) He's even got a wide mouth like Jamie. And he can saunter. And even though he's thin, he's muscular and solid. And most importantly, he can ACT. Joe Mazzello impressed me more than any actor has in a long time. I'm showing you two videos because you really have to see him move and speak to understand why he'd be so perfect as Ian.
Jenn M made a really great comparison: Joe Mazzello's character comes home from war a completely different person... just like Ian Murray comes home from the Mohawk a very changed man, indeed. Both of these characters begin as boys, but become men in front of our eyes... due to their brutal surroundings. I'm telling you - if you didn't see The Pacific, try to rent it when it comes out on video.
My older Geillis Duncan would be played by Cathy Moriarty. She was my Geillis when I read Outlander... but I always figured she was too old to play the part. Imagine my THRILL when she showed up 20 years later in Voyager!