CD shops in Sydney, Auckland, & Singapore

My wife and I are doing a 31 day cruise from Sydney, Australia to Singapore in February. Wondering if there are any shops in any of these three cities that would stock Japanese imports of CDs or Blurays? We are spending a week in Sydney before the cruise, staying at the Sydney Harbour Marriott at Circular Quay. We have a day free in port in Auckland, New Zealand, and are staying an extra week on the end of the cruise at Singapore Marriott Tang Plaza. Any good stores within reasonable distance in any of these cities? We have many other stops, but the wife has loaded us up with day long shore excursions, so these are the only three potential shopping cities.