Thai Crab and Mango Salad

Name: Thai Crab and Mango Salad
Ingredients: 1 cup seasoned rice vinegar; 1/4 cup plus 1 tablespoon sugar; 2 garlic cloves, minced; 2 mexican red chiles, seeded and minced; 3 carrots, peeled and julienned; juice from 1 lemon; juice from 1 tangerine; 1 shallot, minced; 2 tablespoons fish sauce; 1/2 teaspoon sambal oelek; 1/3 cup water; 2 mangoes, peeled and julienned; 2 cucumbers, peeled and julienned; 2 bunches watercress, washed and thick stems removed; 1 tablespoon basil paste; small handful cilantro, chopped; 1 pound jumbo lump crab; 3 scallions, thinly sliced