There's a shop in Wisma Merdeka (beside the Hyatt) in KK that has all the Borneo wildlife books you could want. The book is also available in Kinabalu HQ, just back from there.
The older Mackinnon / Phillips book is also available through the HK library. I recommend learning as many of the calls as possible through xeno-canto before you go. And bring an umbrella.
Dylan