Ray Stevenson - He looks the closest in my minds eye to Reacher but he may be a little old for the role.
Armie Hammer - Almost as good as Stevenson but can play the younger Reacher also. His appearance in Mine sold me.
Joel Kinnaman - Maybe a little short, but he has the aura of Reacher.
Joe Manganiello - The right height and physically imposing.
My son is a TV and Film editor and has worked for Sony, Netflix and Paramount. He said that everything about the Jack Reacher Amazon project is locked up tighter that anything he has seen before. Hopefully, someone will let something slip - he has his ears on it.
You're welcome. Yeah. I'll try to do more to help out. I'm not familiar with all aspects of the franchise, so I'd have to read more and learn more about it to be able to help out as well as I can, but I'll do my best.