What is the most central city to stay to be able to visit Fenghuang, Wulingyuan and Zhangjiajie?

I am thinking of flying into Changsha and visit all these places. Or is there a better place to stay that is most central to all these three places. Will 8 days be enough? Or do you have any alternative option, I am open to suggestion. Thinking of flying out in middle of October.