Sweetmango,
I went on a search for just the thing you're looking for a while back and came up with Nature's Plus Energy unsweetened, unflavored protein powder. I'm very picky about taste (don't like the aftertaste of some of the powders) and I found this one is great - no aftertaste and also it makes a shake very thick and rich (so you might need to add more water). It's also lowcarb and nondairy - 1 scoop is 2 carbs, I think.

It is made of soy, so anyone who is sensitive to soy might not be able to use it. Also, check the can to make sure that it really is unsweetened and unflavored and 70 calories/2 net carbs per scoop. I bought a can without lookin at it and it turned out to be 160 calories and something like 18 grams of carbs!

Hope that helps!

Tam