Cook beef and drain. Stir in beans, tomato sauce, taco sauce, chili powder and garlic powder. Heat to boiling. Place chips in ungreased 12x8x2-inch baking dish. Top with beef mixture. Spread with sour cream. Sprinkle with onions, tomatoes and cheese. Bake, uncovered, at 350F for 20-30 minutes or until hot. Arrange additional tortilla chips around edge of casserole. Serve with shredded lettuce, chili peppers and taco sauce, if desired.