Place half of the mango, lime juice, ginger, and chipotle peppers in sauce in a blender or food processor. Cover and blend or process until smooth. Transfer to a very large nonmetallic container. Repeat. Stir together the mango mixtures, orange juice, and salt. Cover and chill overnight or up to 2 days.
Serve mango mixture in small stemmed glasses or demitasse cups topped with about 1 tablespoon Creme Fraiche. Sprinkle each serving lightly with ground chile pepper or chili powder. Serve with small spoons. Makes 50 appetizer servings.
Beat whipping cream and sour cream in a large mixing bowl with an electric mixer on medium speed until soft peaks form. Cover and chill up to 2 hours. Makes 4 cups.