Chop lettuce, avocado, tomatoes, and roasted red peppers. Then combine first 8 ingredients in a bowl and toss. Next preheat grill. Rub steaks with chili powder, cumin, chipotle powder, garlic powder, and salt & pepper to taste. Next grill steaks for around 8-9 minutes or until desired temperature. Take steaks off the grill and let them sit for around 3 minutes. To prepare the dressing combine sour cream with next 6 ingredients. Toss salad with dressing. Top salad with crushed tortilla chips. Finally, slice steak and serve on top of salad.