Ryan, You should be able to get a 30 day extension of your tourist visa, but will maybe need to go to the immigration office nearest where your address notification Phetchaburi? After that you can do a couple border runs closest wherever you're gonna be (that allows them - some are very picky). - This is provided you haven't already done any runs. Your budget is another matter and not for this site. Good luck...
Also, the bank accounts must be in your own name. Joint accounts are not considered for your visa requirements.....I also assume your Thai wife will use her Thai passport/ID card when she arrives....Unless she is already here...As Tod says don't stuff about. You haven't a lot of wiggle room considering holidays over the period....
You'll need a re-entry permit to come back into Thailand OR get a visa exemption when you return. Or return and transit Thailand to continue your homebound flight.
If you were married to a Thai outta NZ an alternative to having a ceremony here and run with her married surname, is to get the NZ marriage Cert translated and validated, go to Amphoe Office where wife wife is still registered and have her name changed to the new "Farung" surname. They give you a pink certificate with green and yellow and blue floral type border, which shows her new name. Her Thai ID card and Thai passport will then also be in the farung surname...
I got my "O" at Vientiane no problem. Had the paperwork, and my Thai wife with me. Just looked at my wife, didn't bother talking with her at all just said ALL GOOD...Come back tomorrow.. I never started having any problems until I used a visa service to get my first 12 month extension. They did it at Roi Et, even though they knew, and had my BKK condo lease agreements address etc...They did two subsequent 90 day reports then stopped providing them. Only found out about the Roi Et registration when I went to CW to do a 90 day report.
..."UNBROKEN" means that any travel outta Thailand must have been under a re-entry permit? Thereby not requiriung a new Visa application, nor affecting the extension of stay?