For coyote loads look to Blue Dot, Super Field, and Longshot. WEIGH each shot charge, with big pellets you will have a bugger of a time getting enough pellets in the load to make the appropriate weight. Go to Ballistic Specialties for the wads you will need.
Longshot would be where I would start. I've loaded and shot about 250K shotshells, and tried just about all the powders available.