LASORS makes it perfectly clear that flight training must be completed in the same state as the theoretical knowledge examinations except in circumstances agreed by two authorities. At present, the only such agreement in place is between the UK and the Republic of Ireleand.
If you are intending to take the TK exams in the UK and the flight training in another member state, you will not be able to get the licence issued in the UK. You would be well advised, before parting with any money, to obtain confirmation, preferably in writing, from the authorities concerned that what you intend to do is acceptable to them.