What state are you in, as it might be a good idea to get music from local native performers, You can call the BIA Beareau of Indian Affairs, part of the dept. of the Interior, in Washington DC, and they can give you a listing of reservations in your area. There is no place in the US where you are far from one. Call the tribal council, or whatever the governing body is called, and I am sure they will recomend who ever their local tallent is. Most midwestern native nations have drum circles, and some east coast nations do as well. I am presuming you are in the US! If you are not, I can forward this to my friend who works for the Musium of the American Indian, in NY, in the film Deptartment, who writes articals on native culture, and is, of course, native herself. BUT! If you can go the extra mile to have local natives take part, it may introduce you to neighbors that have issue your church may wish to understand and offer cooperation on... (on which to offer cooperation to be gramatically correct...)
All the best
Larry