I'm sorry, I guess there isn't a book -- maybe I just misinterpreted the "Based on the story by..." notice in the beginning.
I'd love to see the UK version - but I don't see it on Netflix.
But the ending to the US version, which I won't give away, ...well... was kinda weird/bizarre/abrupt/out-there and almost comical. I know they patched the ending in when they found out it wasn't going to Season 2, so at least I commend them on ending it. But... well... lol.