Preheat oven on broiler setting. In a large bowl, combine the fresh tomatoes, sun dried tomatoes, garlic, olive oil, vinegar basil, salt, and pepper. Allow the mixture to sit for 10 minutes.
Meanwhile, cut the baguette into 1/2 to 3/4-inch slices. On a foil lined baking sheet, spread some olive oil, then arrange the baguette slices in a single layer. Brush with olive oil on both sides. Broil for 2 minutes, until slightly brown, then flip and broil for an extra 1-2 minutes until golden.
Divide the tomato mixture evenly over the baguette slices. Top the tomato mixture with mozzarella cheese. Broil for 5 minutes, or until the cheese is melted.