To prepare marinade, combine vinegar and salt in large bowl, stir until salt is completely dissolved. Add shallots, chives, lemon juice, and pepper, mix well. Slowly whisk in oil until well blended.
Add tomatoes to marinade and toss well. Cover and let stand at room temperature 2 to 3 hours.
To serve, place 3 plum tomato quarters on each of 8 salad plates. Add 2 slices yellow tomato, 4 cherry tomato halves and 4 pear tomato halves. Garnish each plate with sunflower sprouts, if desired. (Or, place all marinated tomatoes on large serving plate.)