If it was me then I would use the blackberry, but that's me, I suppose it's a matter of choice as both will work in turkey, I would make sure whatever one you take with you, you get it unblocked therefore you can use it with any sim and any network, normally costs about £10 to unblock the phone here in the UK, don't take it to your network supplier A/ they may not do it, and B/ they may charge you and arm and a leg to do it as its a contract phone, also is the phone still theirs until your contract ends??? is your contract 12, 18, or 24 months and when did you start the contract???
Plus you can connect to any of the free WiFi networks in any of the cafes, just ask for their connection and password
Good luck with your move, I hope you enjoy your retirement to turkey