6 hour layover at Guangzhou (International from London then on to Auckland New Zealand)

Oh, don't worry. There are several nice restaurants, duty-free shops and coffee shop in Departure Hall. In addition, there are chairs in the public area, where you can take a rest.

As I know, most fast food and western food restaurants are located at the 1st Floor of the Terminal Main Building, including Mcdonald's, Oak Tree and KFC. You can also find some shops in this floor which provide interesting souvenirs.