Heirloom Tomato and Bell Pepper Gazpacho



4-5 lbs ripe heirloom tomatoes
2 cucumbers, peeled and diced, divided
1 red bell pepper, chopped
1 yellow bell pepper, chopped
2 shallots, peeled and chopped
8 tablespoons olive oil
2 tablespoons balsamic vinegar
2 garlic cloves
Juice of 1 lemon
4 ice cubes
Salt & pepper, to taste

For serving, optional:
3 tablespoons crème fraîche, thinned with ¼ teaspoon water
1 cup heirloom cherry tomatoes, halved