Highly recommend you read Nutrient Timing by Ivy & Portman.
BCAAs before, during, and after training.
"Consuming protein during your workout will limit muscle protein degradation..."
Don't forget to figure supps in your calorie budget.
It's not a supplement, but non-fat cottage cheese (mostly casein) is great for pre-sleep nutrition as it gives your body slowly absorbed protein to work with during the relatively long time between meals while you sleep.
Just because you're dieting down doesn't mean you can skip meals. They may be smaller, but you still need to be eating six or seven meals a day.