If using thawed frozen lobster tails, cook in pot of boiling water until almost cooked through, about 6 minutes. Drain. Cool. Using kitchen shears, cut lobster shells open. Remove lobster meat; cut into bite-size pieces. Discard shells. Puree 4 cups corn with 1 1/4 cups broth in processor until almost smooth. Saute bacon in large pot over medium heat until crisp, about 5 minutes. Transfer bacon to paper towels. Pour off and discard all but 3 tablespoons drippings from pot. Add onions to pot; saute until light golden, about 5 minutes. Add remaining 4 cups corn; saute 3 minutes. Add carrots, celery, and cayenne; saute until vegetables soften slightly, about 5 minutes. Add clam juice and 1 3/4 cups broth; simmer 10 minutes. Stir in corn pure and whipping cream; simmer 5 minutes. Season with salt and pepper. (Lobster, bacon, and soup can be prepared 1 day ahead. Cover and chill lobster and bacon separately. Cool soup slightly; chill uncovered until cold, then cover and keep chilled. Bring bacon to room temperature and bring soup to simmer before continuing.) Remove soup from heat; stir in sour cream. Melt butter in medium nonstick skillet over medium heat. Add lobster meat and saute just until heated through, about 2 minutes. Ladle soup into bowls. Garnish each serving with lobster pieces, bacon, and chives and serve.