Indy, I do not know what your situation is, but your location is down as Thailand, is this permanent (you live there as a resident) or are you only there for a time.
There are a number of schools that have instructor programs, generally though it involves taking most of the ourses that each individual school run over a period of time and then sitting an in house test and this can be a costly process.
Wayne's suggestion of gaining a broad spectrum of knowledge and skills is probably the best and then attend a few courses with schools, if they like you and you are helpfull to others giving good sound advice they may see you as a potential instructor and ask if you want to do work as an instructor /apprentice.