Isopure is fine, but I would get protein off True Nutrition. It's much cheaper and if anything it's higher quality.
+1, It's as clean as iso pure. Especially if you stay with the unsweetened flavors and then add stevia. Obviously taste isn't going to be as good but it is more of pure protein. If your looking for flavor the premium flavors only have 1-2 carbs per scoop and they have way more flavors then ISO-Pure.