How about a nice baked ham? You could get a healthy one from a market, or bake your own the day before. Have it sliced on a large platter. On one side of the ham, set out healthy rolls and some sliced cheese choices, mayo/mustard, etc, so people can make a sandwich with it. On another side of the ham, have thinly sliced baguettes and a bowl of finely chopped olives, tomatoes, capers and red peppers in a light olive oil and red wine vinegar dressing, and sliced fresh mozzarella, and people can make a small fresh open-faced bruschetta. On another side of the ham, place healthy crackers and a homemade cheese spread or cheese ball, and some fresh small vegetables (grape tomatoes, baby carrots, diced zucchini). That way, the ham is your one main choice, but with three options: the hungry people can make a delicious sandwich, and the lighter eaters can have bruschetta or simply an antipasta plate. All of that can be prepared the day before if tightly wrapped and refrigerated, except for the sliced baguette. One the day of the Communion service, all you have to do is set things out. It's kind of the appetizer snacks and the meal all in one.