1. Whisk 1/4 cup pepper sauce, oil, garlic and 1/8 teaspoon pepper in a large bowl until blended. Add chicken and toss to coat. Cover with plastic wrap and marinate in the refrigerator 30 minutes.Make Blue-Cheese Dressing::
2. Meanwhile, stir sour cream and mayonnaise together in a small bowl. Stir in cheese and lemon juice.
3. Heat broiler. Place chicken on a jelly-roll pan in a single layer. Broil 6 to 8 minutes, turning once, until cooked through.
4. Spread each tortilla with 2 tablespoons dressing, leaving a 1-1/2-inch border. Divide and arrange strips of lettuce, chicken and celery about 1 inch from the bottom edge of each tortilla. Combine remaining 1/4 cup red pepper sauce and 1/8 teaspoon pepper in a small bowl; drizzle over celery. Tightly roll up tortillas; wrap in waxed paper. (Can be made ahead. Refrigerate up to 2 hours.) Cut in half through paper to serve.