I have played on blackrock since release, though I let my subscription run out as i have lost interest in the game.
Generally the oceania servers + blackrock (which was the unoffical australian server at launch, due to there not being any oceania servers then) will have guilds like you are looking for. 2am is a fairly late server time to be starting, as 8pm eastern australia is 1am server. For a 2am server time i would possibly suggest trying to find a guild from singapore, as they are a couple of hours behind us.
I am not sure about other guilds, but mine does not let people join that are not part of oceania region, as everyone that did was around for a month and either just dissapeared, or stopped raiding at midnight and joined a us guild due to whatever reason.
Good luck.