Watch some Randy Anderson Videos on youtube and just do what he does. I would hate to know how many coyotes he has killed in his lifetime. Primos sells his line of calls and from my experience they are pretty good.
Also, it wouldn't hurt to Learn many different distress sounds from fawns all the way to mice on open and closed reed calls. The more sounds you have in your arsenal the better, especially on educated coyotes. Educate yourself with coyote vocalizations and you should do just fine. Good Luck!