1. Sort and wash beans; place in a large bowl. Cover with water to 2 inches above beans; cover and let stand 8 hours. Drain beans.
2. Sprinkle pork with 1/4 teaspoon salt and 1/4 teaspoon pepper. Heat oil in a large Dutch oven over medium-high heat. Add pork to pan; cook 6 minutes or until browned, turning occasionally. Remove pork from pan; reduce heat to medium. Add onion and carrot to pan; cook 8 minutes or until lightly browned, stirring occasionally. Add garlic and tomatoes; cook 2 minutes, stirring occasionally. Tie twine around parsley, celery, thyme, and bay leaf to secure. Add pork, beans, 4 cups broth, 2 cups water, and herb bundle to pan. Bring to a simmer; cook, covered, for 2 hours or until beans are tender. Stir in remaining 1/4 teaspoon salt and 1/4 teaspoon black pepper. Cool bean mixture to room temperature; cover and chill overnight.
3. Preheat oven to 400°.
4. Arrange duck confit legs in a 13 x 9–inch baking dish. Bake at 400° for 15 minutes or until thoroughly heated. Remove skin and meat from bones; shred meat into large pieces. Discard skin and bones.
5. Reduce oven temperature to 325°.
6. Bring bean mixture to a simmer over medium-low heat; stir in duck. Bring remaining 4 cups broth to a simmer in a medium saucepan; pour evenly over bean mixture. Bake at 325° for 2 hours. Reduce oven to temperature to 275°.
7. Heat a large skillet over medium-high heat. Coat pan with cooking spray. Add sausage to pan; cook 6 minutes or until browned, turning occasionally. Cool slightly; cut into 1-inch pieces. Stir bean mixture; add sausage pieces. Place bread in a food processor; pulse 10 times or until coarse crumbs measure 1/2 cup. Sprinkle breadcrumbs evenly over cassoulet. Bake at 275° for 1 1/2 hours. Let stand 20 minutes before serving.