To prepare gazpacho, combine first 9 ingredients. Place one-third of vegetable mixture in a food processor; process until smooth. Pour puréed vegetable mixture into a large bowl. Repeat procedure with remaining vegetable mixture. Cover and chill.
Preheat oven to 375°.
To prepare garnish, place bread in a small bowl; drizzle with 1 teaspoon oil, tossing gently to coat. Spread bread mixture in a single layer on a baking sheet. Bake at 375° 10 minutes or until golden brown, stirring occasionally. Cool to room temperature. Place 3/4 cup gazpacho in each of 8 soup bowls. Top each serving with a few croutons, 2 tablespoons quartered tomatoes, and 1 tablespoon cucumber.