Saving Private Ryan is not historically accurate after the first 20 minutes or so. Once the beach head is secure on Omaha the movie plot breaks from history and goes to story.
Far as violence goes I'd probably have a hard time showing Saving Private Ryan to even a lot of adults. It's that brutal, and that realistic. My late Grandfather said the only thing missing was the smell...if they can handle Ryan's violence though they should be able to handle any of the others.
You may consider The Longest Day instead of Saving Private Ryan. It's more historically accurate I think, the violence is still there of course, but it's 50's, 60's violence which is a lot tamer than even our current PG standards.
The Patriot also not historically accurate, but close enough. There is a few speeches that are worth noting, even if they are based on several real speeches.
Not sure on the accuracy of Glory, but it ranks on my "must see war movies" list, dealing with the Black infantry in the Civil War. Violence can be bloody at times, but since the movie was made in the 80's or early 90's again I think our current PG standards are worse in some cases.
Thanks to all of you that have replied.
Your input has been so helpful to us.