I am also trying to get the JAA ATP, I have the FAA ATP but as you have found, that means nothing in the UK. I have investigated the ground schools in the UK but there are also ground schools in the US which offer the JAA exams. The schools in the US are a lot cheaper than in the UK. So far, I have only found schools which do the fixed-wing ATP, not helicopters. I believe there are only two of the 13 or 14 examinations which are different for helicopters.
Does anyone know if there are any schools in the US where you can do the helicopter examinations and preferably the flight test too? I have been in contact with HAI in Titusville, FL and they can only do the flight test, not the theory.
Please help!