Preheat oven to 450°F. Cut bread horizontally in half. Place bread halves, cut side up, on separate baking sheets. Mix onions and 6 tablespoons oil in small bowl. Season with salt and pepper. Reserve 2 tablespoons onion oil and spread remaining onion oil over bread. Top with cheese.
Sauté Italian sausages in large nonstick skillet over medium-high heat until cooked through, breaking up with spoon, about 7 minutes. Divide sausage among bread halves. Bake pizzas until cheese melts and bread begins to crisp, about 10 minutes.
Meanwhile, heat 1 tablespoon oil in each of 2 large skillets over medium-high heat. Crack 4 eggs into each skillet. Sprinkle with salt and pepper. Cook 2 minutes. Remove from heat and let eggs stand in skillets while pizzas bake.
Arrange 4 eggs atop each pizza. Spoon reserved onion oil over eggs. Cut each pizza between eggs into 4 pieces.
TEST-KITCHEN TIP: Having brunch? Assemble and chill the pizzas one day ahead. Then bake and top with fried eggs at mealtime.