You should also consider getting a non-immigrant O visa. I am not sure if you can get it in your home country but you can come as a tourist and get a non-O inside Thailand and then 90 days later apply for a 1 year extension. You will have to open a Thai bank account as soon as you get here to deposit the 800,000 baht. The 1 year extension is the same extension that those of us with an OA get each year. The non-O does not have an insurance requirement.
Get an OA before coming here. You use money in your home country bank account. While here open a Thai bank account and start depositing every month. At the end of the first year of your OA leave and kill that visa. Then return and get an O visa and then 1 year extension. You will have to purchase health insurance to cover that first year on an OA.
I have been on an OA since 2017. I actually bought my Thai insurance before there was a requirement. If I had to start over today then I would arrive as a tourist and pursue a non-O. It requires a few more steps to get to your 1 year extension. I just like the idea of decoupling the insurance from the immigration process. Also, most of the visa changes have been occurring with the OA and not so much the non-O.