You do not the insurance for a non-o visa or a extension of stay based upon retirement applied for at immigration here.
A Non-OA visa applied for at a embassy or consulate for retirement requires requires 12 months of medical insurance to apply for it. The OA visa allows unlimited 1 year entries from the day it is issued,
If you get a single entry non-o visa you can apply for the one year extension at immigration. To apply it requires 800k baht in a Thai bank for 2 months on the day you apply.
Your wife can apply for a non-o visa and extension of stay for being a member of your family and does not require any financial proof.
To travel if you have the one year extension of stay you need a re-entry permit to keep your extension when you enter the country. A single re-entry permit is 1000 baht and a multiple is 3800 baht.