Preheat grill to medium heat; grease grate well. Stir olive oil with garlic; brush half over Ciabatta slices. Season chicken with salt and pepper; toss with remaining garlic oil.
Grill chicken until cooked through, approximately 5 to 7 minutes per side; let stand for 5 minutes. Meanwhile, grill bread until grill-marked and toasted, approximately 1 or 2 minutes per side. Chop grilled bread and chicken into 1-inch (2.5 cm) pieces.
Toss together bread, chicken, lettuce, tomato, cucumbers and green onions. Divide among 4 plates; top with avocado, eggs, blue cheese and bacon. Drizzle with dressing.