Visit to Great wall

Hi, will b visiting Great wall on June1/2nd with family(old person and kids).Which is better Badaling or Mutianu or simatai.instead of walk, can cable cars b a better option to view the entire wall section. if we select cable car,then can we plan to cover badaling & Mutianu on the same day.pls suggest, i do not wish to skip this wonder on the land of China.how much time it takes if we go walking.which section of the wall is shorter and are cable cars available in all the sections.