Can my wife and I combine our finances for the Non-O-A visa requirements when applying in Thailand?

Okay lets sort out what you're trying to do first.

You're going to get a year long, multi-entry Non-Immigrant Type O-A visa from the thai consulate in your country BEFORE you wing your way here right? That's the visa that requires a police background check, a medical certificate and you can use the money in your bank account in your country to meet the financial requirements.

You're confusing the requirements for a yearly extension of stay gotten INSIDE the country with the requirements for a year long Non-O-A visa gotten from OUTSIDE the country at the thai consulate. They are totally different.

You follow the information on this link to get one from the thai consulate in London. Scroll down to the Non-Immigrant Type O-A (Long Stay), That's the visa you two would want to get.

-Non-Immigrant-visas.html