Bus station for direct bus for shantou

We are a group of 4 seniors arriving in Xiamen enroute to Shantou. Our flight touched down at 2 pm.
Is there a afternoon bus to Shantou and if not please advise which hotel is nearest to bus station for boarding bus to Shantou and what is the time of departure of this bus and is it convenient to buy ticket only on day of departure or need to purchase them in advance.