I'm from Australia too, and buy my game cards from GAME UK online have been since last year. No problems what-so-ever ^^

(btw, doesn't matter what server you're on~)

+9:30, same timezone as me :3 as for the time servers will be up:
[Date & Time]
Apr. 24, 2014 from 6:00 to 12:00 (GMT)
*Completion time may be subject to change.
So about 9.30pm