I have an FAA and JAA licence. I converted my IR to JAA in Europe. Good if you want to get that first time pass.
Best option is to do your IR in UK/IRL with a good reputable school that will prepare you for anything on the day of the test. The last thing you need is an IR from some "trained monkey emporium" that will just teach you to pass a test.
Also bear in mind a good reputable school will be able to give you a good flying reference when you go for a job. That will count. Thats why I've chosen a good school some where in the British Isles for my renewal.
Best of luck, Cessnagirl