Make the two boxes of jello up according to package directions. Stir very well until it is completely dissolved. Pour into a very large  cassarole dish. This will make too much for a regular 9 x 12 dish, use a larger one, or plan to split it into two dishes.  Layer the oranges and pineapple into the jello. Top with the mini marshmallows, and put the entire thing into the refrigerator to cool and set. Once set, combine the sour cream and Cool Whip well by hand. Smooth the sour creme/Cool Whip mixture over the top of the marshmallows. Sprinkle the cheddar cheese over the top. Cut into squares and serve.