Hi，
There is only one Giant Panda Base in Chengdu, that is Chengdu Research Base of Giant Panda Breeding which is located 10 km north of Chengdu, is one of the most important giant panda conservation and protection centers.
The one you mentioned is in Yaan City which is about 160km away from Chengdu. After the earthquake happened in 2008, most of the giant pandas in captivity at Wolong Panda Protection Zone were transferred to Bingfengxia Gorge Base which had few pandas before.
It’s hard to tell you which one is better. It depends on which places you want to travel. If you want to go to Jiuzhaigou, you may go to Bingfengxia. If you don’t have so much time, you may visit Chengdu Research Base of Giant Panda Breeding because it’s not far away from downtown.
If you still have problems concerning tours in Chengdu, you may email me, I hope I can do some help.

Dear Ms.Zhong,

Thank you so much for your kind information. It's very informative. Will send you an email if i may need your help:-)

Kind Regards,
May.