It comes to BBQ camping, I think charocal BBQ is better than gas bbq, because they are more portable. Because you just have 5 five family members, there is no need to take a party BBQ with you, you just need to take a small and portable charcoal BBQ. About which one is the best and suit for you? I am afraid i have no idea, after all, everyone has different ideas about the same BBQ. In my view, I like Landmann charocoal BBQ, especially picoolino charcoal BBQ ( http://bit.ly/YrDr4a ) , portable and looks great. I just got one in turquoise.
Good luck to you and have a wonderful BBQ trip.