1. Preheat oven to 350°. Bake almonds in a single layer in a shallow pan 4 to 6 minutes or until toasted and fragrant, stirring halfway through.
2. Prepare rice mixes according to package directions.
3. Meanwhile, melt butter in a large skillet over medium heat; add celery and onions. Sauté 10 minutes or until tender. Stir in shrimp, next 6 ingredients, rice, and 1 1/2 cups of each cheese. Spoon mixture into a lightly greased 15- x 10-inch baking dish or 2 (11- x 7-inch) baking dishes. Top with breadcrumbs.
4. Bake at 350° for 35 minutes. Sprinkle with remaining 1/2 cup of each cheese, and top with toasted almonds. Bake 5 minutes.
To Make Ahead: Prepare as directed in Steps 2 and 3. Cover with aluminum foil, and freeze up to 1 month. Remove from freezer, and let stand at room temperature 1 hour. Toast almonds as directed in Step 1. Bake casserole, covered, at 350° for 30 minutes. Uncover and bake 55 minutes to 1 hour and 15 minutes or until thoroughly heated. Sprinkle with 1/2 cup shredded Monterey Jack cheese, 1/2 cup grated Parmesan cheese, and toasted almonds. Bake 5 more minutes.