Slice tops off of green peppers; remove seeds and membranes, and rinse well. Bring a large pot of water to a boil. Add peppers and cook for 15 minutes, or until tender-crisp.
Place sausage and onions in a large, deep skillet. Cook over medium high heat until evenly brown. Reduce heat to medium and stir in tomato soup, water, chili powder, garlic powder, salt and pepper; bring to a low boil. Reduce heat to low, stir in 3/4 of cheese and simmer for 1 hour.
Meanwhile, preheat oven to 350 degrees F (175 degrees C).
Prepare instant rice according to package instructions. Fluff with a fork and then stir into tomato mixture. Simmer for 30 minutes.
Spoon rice mixture into peppers.
Bake in preheated oven for 30 minutes. Sprinkle remaining cheese on peppers and place under broiler until cheese is melted and bubbly.