I went out to HAI in 2004 with the idea that one needed to do the FAA licences to get the magic 1000 hours before returning back to the UK. In hindsight I should have come straight back to the UK, done the IR and got a job. I've been lucky as the North Sea has recruited heavily since the start of 2007, but all indications suggest that the main 3 companies willl continue to recruit until the end of this year and then they will all have reached their pilot quotas. There will be a lot of people in front of you in the queue for jobs (Bristow Academy churn out 18 JAA qualified pilots every 3 months) so be careful before you invest your money!
Best of luck
Barotrauma