I had a friend of mine doing this a couple of years ago, with over 20 years flying in Asia, he wanted to convert back to EASA license. With over 15.000 hours experience Captain on 777, 747, A340, 330 with Cathay. He failed 2 of the exams, and never got around to take the remaining before they lapsed.
The issue is that they are not very relevant to normal operations these days, so they are a bit of a headache. I would recommend Bristol QB and make a plan how to do the exams, not to do all in one go, but make sure you have paced it so you have time to do retakes within the time limit if required.
We had a system where you did 3 exams after 2 months, 6 exams after another 2 - 2.5 months and remaining 5 exams after another 2 months, so a total of around 6 months.
The thinking behind this is that after you have completed all 14 exams, you still have another 12 months left for any retakes. You can retake any exam maximum an additional 2 times, within 18 months from your first passed exam.
Depending on your experience level, you might or might not need to take them trough a training facility. My friend with his experience could just do the exams directly with the CAA.
After completion he would have to do a Sim TR check / LPC.
I would say UK is better to do the exams, however UK is full of uncertainty because of Brexit, so you will to see what is possible.