Go!
Emirates is a modern and expanding airline - one of the few in the world that is still growing. I have heard that Dubai is a very modern and progressive city (by Middle East standards) with a large British expatriate community - great for wife and kids - probably good schools. Add on to that interesting routes and very advanced aircraft (777s!). The alternative is to stay in a contracting British airline industry where sorrow is pervasive and wages seem to be reduced annually.... Also, scheduled flying is probably preferred to erratic charter flying - right?
A few questions for you:
1. Any idea about aircraft type for training for you - A330/40 or 777? Have they assigned you to a type - which would you prefer?
2. Have you seen the Airliner World mag for January (or Feb)? Evidently there is an article about Emirates pilots converting onto the 777 - it may be of interest to you...
Good luck - I'd prefer the dry desert oasis to the cold rain any day!