In small bowl, stir together lime juice, oil, hot-pepper sauce, garlic, oregano, sugar and black pepper. Place steak strips in large plastic food-storage bag. Place onion and peppers in second bag. Divide marinade between 2 bags, about 1/3 cup in each; seal bags and turn to coat steak and vegetables. Refrigerate to marinate several hours or overnight, turning occasionally.
Heat broiler or outdoor grill. Remove the meat and vegetables from plastic bags and marinade; discard any remaining marinade.
Broil or grill onions and peppers about 4 inches from heat 10 minutes or until tender, turning over about halfway through cooking time. Add meat and broil or grill about 6 minutes or until internal temperature registers 145°F on instant-read meat thermometer, turning over halfway through cooking time. Arrange meat and vegetables on a platter.
Serve meat and vegetables with bowls of tomato, cheese, sour cream and guacamole and a plate of warm tortillas.