dont worry about houdini!
i would suggest having a pad, i suspect that you can get one in bangkok (i think that there is a climbing shop in the siam centre) also outdoors shops in singapore (expensive). there are none for rent on tao. at the moment anyway, if james goes back, that may change.
there is some amazing looking bouldering in peninsular malaysia, there was a web page somewhere (search). i found some boulders on Tioman island, Malaysia that had not been climbed before, but nothing much of note. bouldering near to Nah Trang, Vietnam.
good luck.