Any brand is fine as long as there isn't a lot of carbs in the serving, I use Optimum which has 3 grams a scoop. I personally think you should just get a whey protein supplement and not a meal replacemener cause it sounds liek you get enough carbs in your diet as it is.
whey protein is just plain protein. The protein "shakes" as you call them are meal replacements, they contain carbs and some fats in with them. No necessary in my opinion unless you're bulking up and trying to put on some muscle and can't find the time to prepare foods in advance.