Preheat oven to 350°.
To prepare stuffing, combine 1/4 cup boiling water and sun-dried tomatoes in a small bowl; let stand 20 minutes or until tomatoes soften. Drain and finely chop. Combine tomatoes, mozzarella, and next 6 ingredients (through egg) in a food processor; process until smooth. Spoon 2 tablespoons stuffing into each shell. Set stuffed shells aside.
To prepare sauce, heat oil in a large skillet over medium-high heat. Add onion, bell peppers, and garlic; sauté 6 minutes or until tender. Place onion mixture in a bowl.
Coat pan with cooking spray; return pan to heat. Add sausage, and cook 6 minutes or until browned, stirring to crumble. Add wine; cook until wine is reduced to 2 tablespoons (about 3 minutes). Stir in onion mixture, tomato paste, and next 5 ingredients (through tomatoes); bring to a simmer. Cook 25 minutes or until slightly thick.
Spread 2 cups sauce over bottom of an 11 x 7-inch baking dish coated with cooking spray. Arrange stuffed shells in a single layer in pan; top with remaining sauce. Sprinkle 2 tablespoons Parmesan over sauce. Bake at 350° for 40 minutes or until bubbly.