Hi! We're visiting Hongkong in September 18-21. 2 adults and 2 kids (4 and 6)stay at Causeway Bay. What type of card should i buy? We intend to visit Disneyland, Victoria Peak,Mong Kok, take the ferry and Ocean park..Giant Buddha if possible. Is there a card that would cater to all this areas including 2 way of airport?(The cheapest way) Your reply will be very much appreciated, Thank you.