Preheat large skillet 1-2 minutes on medium-high heat. Preheat oven to 400°F. Place shrimp in skillet, saute for 7 minutes and prepare according to package instructions. Pour off 1/2 cup of scampi butter and reserve for crostini. Brush reserved scampi butter on bread slices. Place on baking sheet and bake for 10 minutes. Add tomatoes, lemon zest, horseradish, Worcestershire sauce and hot sauce to skillet. Stir to incorporate. Bring to simmer. Portion shrimp into serving dishes. Garnish with celery sprigs and garlic crostini.