I'll be diving in that part of the world in October. This is what I'll be taking, and I expect it will be more than sufficient.
10W HID (apart from the obvious regular use, night signalling)
Princeton-tec strobe
Starflash mirror
Storm whistle
3' oral-inflated yellow SMB (has my whistle ziptied to it)
5' regulator-inflated orange DSMB
Rescue Streamer
My wife carries most of the same items. Thinking of some items like the rescue streamer, mirror & strobe into an "oh-sh!t" pocket on a camband, as these are the items least likely to be used, and I want them on me but out of the way. Might add a buddy leash to that pocket too. The 3' SMB/whistle is always clipped off on my SPG D-ring every dive anyway for quick deployment (have only had to use it once, but when you want it, you want it in a hurry!), and the 5' SMB has it's own pocket on the backplate. Might add a dive-alert.