If I can give one bit of advice, make sure you change your money at a 'Crown' exchange booth. So many people see a better rate advertised but when they get their money change they are ripped off, and I don't mean by a few pence.
You will find 'crown' exchanges all over Sunney Beach so please don't fall foul of the rip off merchants.
I would agree that it is best to change Sterling Cash but for your own sake take Sterling Travellers chaques, it's the same as anywhere else in the world, you never know!

Have a good holiday