@Mandrake: I've made some posts about A. confusa at DMT-Nexus, and also a page about it at DMT-Nexus wiki. I could copy them here, if you find it useful. I am growing A. confusa on my balcony in Bangkok, and it does fine, though tends to stretch a bit more than it should. Perhaps it's too hot for it. (It does grow in the Philippines though, where the climate is similar to Thailand, but my seeds had been collected in China.)
@Bach: Peyote is really a no-brainer here. You just need to have a roof to protect it from rain during the rain season. Other than that, all cacti seem to love humid air and strong sunshine here, and they grow in Thailand faster than in their natural habitat. Peyotes do not go dormant here as they do under natural conditions, but grow year-round.