I would make one suggestion for change. Ditch the military style steel butt plate and get the shotgun stock and steel butt plate. That .50-90 is going to have some fairly stout recoil off the bench and you will be able to shoot it better and longer (in more comfort) with the shotgun plate. And to develop a good load for it will take some bench time. No need to destroy your shoulder. The 30 inch barrel is a good choice and having the military ladder sight is too. Depending on what you are hunting, it is probably a much better choice than the tang sight but you will want it for shooting for fun.
Good luck on your deployment and thank you for your service.
I went with a shotgun style, they call it a Traditional Steel Shotgun, and on the order form they leave off the "shotgun".