Nitrix is an NO booster supplement and cellmass is a post workout amino acid and carbohydrate supplement. Honestly I doubt you will notice much from either supplement but neither contain any protein. You STILL need to use a protein source like a whey isolate after your workout to replenish depleted amino acid levels and start rebuilding the muscles you broke down during you workout.
You really need to be a smart consumer in today's market and do your research. Look at the ingredient list and supplements fact panel on every supplement before buying it.
For a whey protein - you want to see nothing but that in the ingredients list. Whey protein, natural flavours, a natural calorie free sweetener like stevia and then maybe some salt, soy lechitin and cocoa powder. There are a lot of good products on the market. I personally use isolation from n2bm.com. A good whey isolate should be pretty much fat and carb free. Isolation has 26g protein, 1g carb, 0g fat per 30g scoop.