Is the O-A Visa the best option for Australian citizens over 60 spending six months in Thailand?

Thanks James and Joe. For tax reasons I need to limit my annual stay in Thailand as a resident to less than 180 days in a year. Maybe the multi entry tourist visa for 6 months is a better option as I am not taking up residency outside of Australia. I assume with the 6 month multi entry tourist visa I would have the slight inconvenience of having to get say a cheap flight to Vietnam or another SE Asian country every 60 days and then flying back to Thailand after a day or two?

Thanks Barry. I believe that would mean 60 days per visit. What if I wanted to stay continuously in Thailand for 6 months and only departing at the end of the six months?