A school district will usually support, and sometimes help pay for, a MA degree that has to do with teaching, curriculum, etc. It would be extremely difficult to #1
. get the support or $$$ from a school district for an MFA in acting, and #2
. teach while pursuing your MFA at the same time. Most teachers need to earn their Master's during the summer months, or take time off once they've worked a few years in a district and have a continuing contract.
If you want to teach in a high school setting, an MA would be best. If you want to teach at the university level, then earning an MFA would be the way to go.
I'm currently earning my MA in Theatre Production at Central Washington University. Over 80 drama teachers from all over the world are in this program. This program is unique because it's designed for teachers, and it's an MA in Theatre, which I'm passionate about. It occurs during the summer months, so I can still teach my high school and middle school students during the school year. I wanted my MA to be in theatre, so this worked out great for me.
Hope that info helps at least a little!