In a large bowl, beat the powdered sugar and 1 1/2 cups of the sour cream with an electric mixer on low speed until moistened. Beat on medium speed until smooth and creamy. Set aside 3/4 cup of the coconut. By hand, stir remaining coconut into the sour cream mixture. Spoon the frosting into a covered container. Refrigerate at least 6 hours. Heat the oven to 350 degrees. Grease and flour the bottoms and sides of 2 8-inch round cake pans. In a large bowl, combine the cake mix, pudding mix, orange and lemon peel, oil, water, juice, eggs and remaining 1/2 cup sour cream. Beat with an electric mixer on low speed until moistened. Beat on medium speed for 2 minutes, scraping the sides of the bowl if necessary. Pour the batter evenly in the pans. Bake for 28 to 33 minutes or until a toothpick inserted in the center comes out clean. Cool the cake in the pans for 10 minutes. Remove the cake rounds from the pans to cooling racks. Cool completely (about 1 hour). Wrap each cake layer and refrigerate until the coconut frosting mixture is ready to use. Using a long serrated knife, cut each cake layer horizontally to make 4 cake layers. Set aside 1 cup of the coconut frosting mixture. Place one cake layer on a cake plate, cut side up. Spread 1/3 of the remaining coconut frosting mixture (about 2/3 cup) in thin layer over the cake. Place another cake layer over the filling; press down. Spread another 1/3 of the coconut frosting mixture over the cake layer. Repeat with the third cake layer, spreading with the remaining 1/3 of the coconut frosting mixture. Top with final cake layer, pressing down firmly. In a large bowl, beat the whipping cream until stiff peaks form. Fold the reserved 1 cup coconut frosting mixture into the whipped cream. Frost the top and sides of the cake with the whipped cream mixture. Sprinkle and pat the reserved 3/4 cup coconut on the top and sides of the cake. Cover with a cake dome or a bowl large enough to not touch the frosting. Refrigerate at least 12 hours before cutting. Store covered in the refrigerator up to 3 days.