Get the green book as fast as you can. It makes no difference if it's a local or JAA licence. For the application of cash the original issuer (the UK CAA for most of us here) will happily issue either!
The reason for the unholy rush to get an ATPL is that the ******s can't change the rules for the majority of pilots (most of whom would have real problem going back to school to learn how to design aircon and braking systems - me included!) who have an ATPL.