M.M.
I have lived in the Dallas area all of my life - Plano, Richardson, Carrollton, Rockwall, Dallas, Denton, Farmers Branch, Mesquite and Duncanville. I've attended Richardson & Plano schools.
Stay away from Richardson, Dallas and Irving School districts. Look into the outlying areas such as Plano, McKinney, Allen or Rockwall - all have strong school districts. I've heard good things about Grapevine, but I have no personal experience to speak from. Flower Mound and Frisco are surrounded by highways - just too many businesses and traffic in too small of an area.
I think I would go to Austin WAY before I would come to Dallas - there is nothing to do here but eat & shop.
Good luck with your move. I hope all goes well!