If you plan to use them in the way you described then they wouldn't be supplements....they would meal REPLACEMENTS.
Supplementing your breakfast and dinner with protein powder isn't going to help you lose weight. That's just adding additional calories to your diet which all things equal will make you GAIN weight.
My advice: skip the supplements unless you have an obvious deficiency in a particular nutrient. Personally, I'd much rather cook myself a nice 200 calorie breakfast than to mix up 200 calories from a powder and drink it.