I'm taking my daughter to Phuket and Phi Phi for her 21st in April.What would you recommend?

We want to stay in a bungalow on Phi Phi close to the beach and the village.What activities are there to do in Phuket?We are planning on staying at the Horizon Patong Beach Resort.Should we take $AUD or use our keycard for money .Are there ATM's readily available?Thanks