Welcome to flyertalk JAL!

Of course one would suspect that flying in is the best, but I disagree. You have to be aware that the city of GZ and the Pearl River Delta are such a terrible place to be, that going in via HKG with the express train is really your best option. Take your first and last hotel night in HKG and spend as little time as possible in GZ.

The new airport in GZ is also quite far out of town. If it is your first trip to the PRD from Oz you might consider carrying an air purrifier with you. Anyway, you will find out yourself.