For using starcluster to start a amazon cluster in a region other than us-east-1 change the following two things in your .starcluster/config:
1) Add the following lines under [aws info], modify the text in "<>" according to the region and zone where the cluster is set up
aws_region_name = <ap-southeast-2>
AVAILABILITY_ZONE = <ap-southeast-2c>
aws_region_host = ec2.<ap-southeast-2>.amazonaws.com
2) Change the NODE_IMAGE_ID number to the AMI ID of EM-packages-in-the-Cloud-Node-v3.1 for the region where the cluster will be set up.