90 day stamp is on paper that's stapled into your passport so why are you running out of room ???, or if you don't want a piece of paper in your passport then do your 90 day reporting online.
To get this my English wife holds a none O visa based on retirement.
We then had our marriage certificate verified by the British embassy and then translated into Thai, which was then verified by the ministry of foreign affairs which was all done whilst being in Thailand.
big clamp down now on opening up bank accounts without the correct visa. Long gone are the days where they'd accept your cash. This persons best option is to apply for the correct visa in his own country before arriving in Thailand. Then the process is pretty straightforward
you can also get a "dependency " visa which all you have to do is get your marriage certificate verified by your embassy, then translated into Thai and verified by the ministry of foreign affairs. This way only 1 of you (the visa holder) can attach a dependent and only have to deposit 800K or show the 65K (for a full 12 months).
This is what myself and my wife do successfully for the past 6 years.
I don't know if this is different for different countries (we are British).