What are the differences between Non-O and Non-OA visas regarding the 800,000 THB requirement?

A non O is only for 90 days but it can be extended to 1 year once you have a Thai bank account, you will need 800,000bht in your account 2 months before you apply for your extension, every year after you can have the 800,000bht or / month for future years ,also an agent in Thailand can sort your 800,000bht for you if you pay enough.

About the 0 baht must be in thai bank

Ore it's possible to have them in your bank in your won home country

This really depends on if you are going to get an extension of stay each year and live/retire in Thailand, if so you need to understand the following. The non-O does not require any medical insurance and the normal non-O visa gives just you permission to stay in Thailand for just 90 days, once. There used to be and might still be a multiple non-O visa that allows you multiple 90 day stays during a 1 year period, I came over on this 14 years ago but lots of things have changed since. The non-OA on the other hand allows you to stay for a year (so I understand it) so might appear to be better but although both the visas need you to prove funds in your home country the non-OA also requires you to have medical insurance for the full duration of the visa and I believe it still requires that to be with a Thai company although that might have changed. Note that most travel insurance only lasts for 30 days from when you leave your own country even if it is valid for a year. If you are intending to stay full time in Thailand then you will need to get an 'extension of stay' and although both the non-O & non-OA extensions appear the same (same process) the requirement for the extension is based on the original visa (as I understand it) so if you have a non-O visa then the requirement is having the funds in Thailand but the non-OA is having funds in Thailand AND the medical insurance. So if you are going to get the extension then I think it's better to enter on the non-O visa so you are not forced to have medical insurance every year to maintain your visa status but that's not to say that I think you shouldn't have medical insurance as I do but with the non-O visa (and extension) you are completely free to choose how much cover and with who where as with the non-OA you HAVE to have the insurance and it has to be for a certain amount and with an approved company. I'm no visa expert so please check what I've said before making your decision, this is just my point of view from someone who has lived in Thailand for 14 years and has friends with both non-O and non-OA visa (extensions). Sorry it's so long

NON-O (in Thailand). NON-OA (your country)

With an OA you can effectively wait almost 2 years before you have to transfer funds to Thailand. Doing an entry into Thailand just before the Visa expires and having insurance updated you will be stamped in for another year. So you will start the extension process just before year three. You will lose multiple entry benefit on that second year but you can buy a reentry permit as needed.

Aside from the health insurance, police check etc the main difference between the two visas is that the Non-O is a 90 day single entry visa and the Non-OA is a 12 month multiple entry visa which you can only apply for in your home country. The financial requirements for both are the same, you can show money in your home bank

No, your Non-OA gives you a 12 month entry stamp, a Non-O gives you a 90 day entry stmp which will need 800k (usually) in a Thai bank account for 2 months to get a 12 month extension.