I've only been to one Cath Kidston store. It was in Thailand.
I was surprised when I found some authentic Cath Kidston and Amy Butler (and other cutesy patootsy brands) stationery here in the Philippines at ... tan-tan-tanan ... where else but National Bookstore.
Found them at National bookstore Greenbelt 1. Hurry, once the Cath Kidston and Amy Butler fanatics learn that they sell it, they'll be gone in an instant.