Andy: I suffered from a bullying Head, who also had other undesirable behaviour around some pupils. Despite the combined efforts of those of us willing to speak out and the police and Child Protection involvement, nothing was done. Eventually, a few of us gave up and left - in my case taking a sideways move - because the situation became impossible.
I'm sure you'll heed the advice to join a union - I found mine most supportive on more than one occasion. And do apply for that job. You'd be readily available for any supply work there on your day off or you could put your name down at other nearby schools. Failing that, would your wife consider some part time or evening work to help the family budget?
Good luck and I hope things soon improve, whatever you decide to do.