1. Preheat oven 425°. Grate zest from lemons to equal 4 tsp. Cut lemons in half; squeeze juice from lemons into a measuring cup to equal 2 Tbsp. Combine panko, paprika, and 2 tsp. lemon zest in a shallow dish. Sprinkle fish with 1 tsp. salt. Dip fish in 1/4 cup melted butter; dredge in panko mixture, pressing panko to adhere. Place fish on a lightly greased rack in an aluminum foil-lined broiler pan. Drizzle remaining 2 Tbsp. melted butter over fish. Bake 20 to 25 minutes or until fish flakes with a fork.
2. Meanwhile, prepare pasta according to package directions. Melt 2 Tbsp. butter in a large skillet over medium heat; add onion, and sauté 5 to 6 minutes or until golden. Add garlic, and cook 1 minute. Add tomatoes, and cook 5 to 6 minutes or until tomato mixture begins to thicken. Stir in 2 Tbsp. lemon juice, 2 Tbsp. capers, and remaining 2 tsp. lemon zest and 1 tsp. salt; cook 2 to 3 minutes. Remove from heat, and toss with hot cooked pasta, feta cheese, and basil. Serve with fish.