Okay, I've flown in the same areas and first thing is to get some good international training, especially the China segment. I would recommend the smaller GA airport in Singapore, dang can't remember the name, I'll look it up or Universal knows about it, an ex-RAF base. A lot easier place to clear customs. One word of advice, no instrument approaches and the departure is a bit tricky to stay in the airspace confines required by departure. Just keep the airspeed down and you should be okay.
Most ATC controllers at the major cities and en-route in China speak very good English, at least in my experience. You will be talking to Oakland Center all the way across the Pacific.
There is a lot of great food in China and Singapore. Don't pass up the chance to have a drink at the 'Long Bar' at the Raffles Hotel in Singapore. Also lot of great restaurants and bars along the river. I usually stay at the Marriott in Singapore, but there are a lot of really nice hotels there. Most people you will meet in Singapore speak English, same with Australia, okay just kidding about Australia

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More later, still mad at myself not remembering the name of that airport in Singapore.
Oh, one more thing, you must have visas for Australia. Easy to get, but everyone on board must have one. (To tell the truth if you don't have them they probably will give them to you on arrival, but it will really make them mad at you. So just get them ahead of time.)