Visa for China visit

My husband and I , US citizens and residents, are planning to visit many locales beginning in February 2015. Our itinerary begins in New Zealand continuing to Australia, to Bali, Borneo, etc. We are not sure at this time when we will make it to China or what month it will be. We are hoping to have an extensive stay in China. Can we apply for the visa prior to leaving US and enter China 6 Months after? Do we have to have a specific date to gain it and subsequently entry? Can we successfully get one in another country while we are traveling? Thank you in advance for responding to our inquiry,
Cathi