@Tod ********
OK Tod, thanks for the info, I'm glad I asked here.
Assuming that I could try get the extension in the first year with the 65k THB per month banked, what would be the alternative, apply for a Non O in my home country? What would I have to show in terms of finances to apply in the UK for a 90 day Non O?
I am a resident of New Zealand also and have a bank account there and in Australia. Would I also have the option to apply for a Non O in one of those countries? I have no desire to go back to the UK again any time soon, if I can help it!