Your best-head hunters are right on your campus. Smart teachers who love students and love learning tend to know other smart teachers who love students and love learning.
Who are your most effective teachers? Why do they stay at your school? To what do they attribute their success? Based on their answers you should be able to craft your school’s branding model for recruitment. Ask them to recruit friends who want to work in a place that supports the success of effective educators. If they aren’t willing to ask their friends to come, ask them what would need to change in order for them to recommend the school to their friends. See if you can create a climate where only the best educators want to work in your school.