Combine first 3 ingredients in a medium bowl. Cover and chill 2 hours.
Place the Clamato juice in a small saucepan. Bring to a boil, and cook until reduced to 1/2 cup (about 12 minutes). Chill reduced juice.
Add Clamato juice, tomato, jalapeño, and cilantro to scallop mixture. Fold in avocado and crabmeat. Garnish with cilantro sprigs and lime wedges. Serve with chips.