zhangjiajie n changjiang san xia

After landing in Changsha, you can take the airport shuttle bus to West Bus Station. There you can easily take a direct bus to ZJJ. At the hop-on station, buses to the scenic area (national park, wulingyuan, etc.) are available. After visiting, you can go back to ZJJ City.

By "Changjiang Sanxia", do you really refer to Yangtze River Three Gorges? if so, at ZJJ Bus Station, there are direct buses to Yichang, but I forget the timetable. Or take a train to Yichang in around 5 hours. At the local New Century Dock, you can take a cruise to Chongqing (5D4N). On the way, you can enjoy the gorges and the Three Gorge Dam. But it will be cold then. Do wear thermal clothing. At last, it is best to book the cruise in advance.

Including train tickets & hotel booking, transfer services and cruise reservation, I know Travel China Guide can help you. If needed, their contact is traveltravelchinaguide.com!