i ordered 2 maps via dymocks.
Lantau Island and Neighbouring Islands (survey and mapping office lands deparment countryside series) $82 – cheung chau section is about size of an A4 piece of paper. i wouldn’t recommend it.
Lantau I., Cheung Chau & Lamma I. (universal publications) – $25 cheung chau section about the size of one page of SCMP. much better. It also apparently comes in a hanging version which i’m going to order.