Kindly if you could provide a cusomized quote for the itinerary as described below.

I would like to visit the following locations: Hongkong, Shenzhen, Guangzhou, Zhangjiajie, Xian, Shanghai, Beijing, I will be arriving in Guangzhou on the 19th of March 2026 and set to depart from either Beijing or Shanghai depending on which itinerary would be easiest or cheapest on the 28th of March 2026. Kindly let us know if it is achievable given the timescale and if not the alternative.