The shower is coming off if the wall, not ceiling

For me, the higher the better, so accommodate your husband's height and it will be fine for you.

At least 6 foot 6 inches.

Have your husband raise his hands above his head like he's washing his hair. Add 4"-6" to the top of the reach of his hands. That will keep him from knocking it down. Wall mounted rain showers are pretty precarious to begin with. If there is any way to do a ceiling mount, it would be a much sturdier choice!

Thank you for your input. I will have to go back to the plumber and ask him to reduce the height from 8 feet. Appreciate the advice.