applying for G visa while travelling abroad

I hold an Australian passport and will need to transit twice in China to board my flight to Sydney. I will stay in Nepal and Thailand for 3 months and then return to Sydney via China. I'll arrive to Guangzhou international, transfer to Guangzhou domestic to catch a flight to Shanghai Hongquiao airpot, transfer from Hongqiao to Pudong in Shanghai and then, mercifully, just fly direct to Sydney. It seems that I will need a G ype for one transfer and another one for the second transfer. Can I apply in Nepal or Thailand though I am Australian? If I get a full L type I will have to get a 6 months one to cover me for the China transfers at the end of my long holiday. It seems such a waste. I visited China 3 times already and can show my old records in the passport. This might help when applying while abroad. Perhaps they can give me G type at the Guangzhou airport or Shanghai Hongquiao airport?