Slice the lettuce into thick wedges. In a medium-sized bowl, add the mayonnaise, sour cream, buttermilk, salt and pepper, to taste, hot sauce, chives, garlic, and lemon juice. Whisk together, then slowly fold in the blue cheese crumbles. Arrange the lettuce on a serving platter and drizzle with the dressing. Garnish with tomatoes, avocado, and bacon. Serve.