If you finish before 30 June you will get a JAA Licence that will automatically become an EASA licence however; you will have to pay to have it reissued after 5 years. If you apply after 1 July you will get an EASA licence with lifetime validity.
Do I have to start again with my ground exams?
Not much point there aren't any other exams; EASA has none.
The only real difference under EASA is that all exams have to be passed in 6 sittings; so some papers will have to be combined.