Should I apply for a Non-O partner visa in Thailand or offshore, and what are the funds requirements?

If you don't already have a Thai bank account in your name only, it will be difficult to open an account if you don't already have the 90day Non-O, so it makes it easier and faster to get your bank account opened, if you get the 90day Non-O online before you arrive.

Hi i am thai and i have done one for my husband. Offshore is the best. I applied with Canberra Office since i lived in Adelaide. I thought i prepared the documents well , still took me almost a month to open my husband a Thai bank account

Do it before you come over.

You're not going to get around having to deposit 400k in a Thai bank account in your name only at some point.

Because you'll need that in order to get the year extension. Especially as you said your embassy here no longer issues the income verification notary paper.

You can apply for the 90-day non-o visa at a thai consulate abroad showing proof of funds in your bank in your country.

The choice is yours ; move the money into your thai bank account go get the visa,

or

go get the visa using proof of funds in your country come here get your 90-day stamp and then move the money into your thai bank account so it can season the required 2 months before you apply for the year extension.