You need to decide that. As it all depends on whether you need to to be disciplined enough to work on your own, if not go Full time. 2nd Can you afford to stop working and still pay to keep yourself going for a year, if not you will have to work and do it distance learning.
FAA to JAA can be done, just do the 14 ATPL exams, do the 15 hours CPL/IR conversion. But thats the minimum. Expect 20-25 if you have not been flying for a while