Have you browsed this subforum yet? I think there have already been some threads with support for Arabic.
On its German homepage Pocketbook offers some special firmware 2.05 for Arabic for the Pocketbook 602 for instance (here:
http://www.pocketbook-int.com/de/node/608) but I couldn't find anything for the Pocketbook 360+. Maybe you can send an email to their support and ask them for help.