Newfie or Great Dane?

I am wanting one of these dogs but would like to get input of people who have had experience with them. We already have a sheepdog, large and super great with my two small children. I would like to get her a companion but can't seem to choose between the Newfie or the Great Dane. I don't mind the shedding of a Newfie. However the dog should travel well and be good with small children. I had a jack Russell and it stayed at home a lot bc it got car sick--and it wasnt good with kids. Which one-Newfie or great Dane? Help!