Well without doubt you need a will and without doubt you should see a lawyer not just a will writer. There are many possible complications by living abroad involving sharia law, inheritance tax and frozen accounts here on death making it potentially difficult for relatives. We always suggest to our clients to use Mark Nierada, a lawyer, who specialises in this and has been in Dubai for a number of years. You can also find him on the web. I believe he gives an overview initially with no charge. Clients all seem very satisfied
His number is 050 650 8163
Hope this helps.