Do I need a bank statement for the 90-day Non O visa in Thailand, and what about a neighbor witness?

You need it in the bank in your name for the Non-O then it needs to be seasoned for the extension

You need to have the 400K baht IN a thai bank account in your name only BEFORE you apply for the in country Non-O visa.

Most offices require you have a minimum of 15 days left on your current stamp (some require 21 or more)

When you go to apply for the one year extension the 400K baht has to be in the account in your name only for 2 months before you apply.

I suggest you go to your immigration office with your thai wife, talk to them, get the hand out listing the requirements to get the initial 90 day Non-O visa and then the other one listing the requirements for the yearly extension. That's the ONLY way you're going to know.

OR if your profile is to be believed and you're in Korart post on a f/b group related to there and see what people say. Personally I'd slog on over and get the info directly from the immigration office/officer but that's just me 😉