Well, I've only ever used Optimum Nutrition, which I like and consider very cost effective. It's 3g carbs (1g sugar).
There is also low-carb Grow! from Biotest. You can find it at the
Testosterone Nation web store.
FWIW, I'm also on a low-carb diet (I appear to be carb sensitive) but for PPO and PWO, I don't worry about the carbs. However, I also don't consume protein powders outside of the 2 hours PPO and 1 hour PWO very often.
Sometimes I'll use it in cottage cheese, because CC is so flavorless and needs a protein boost. A scoop of vanilla went well, strawberry bit the dust, but still went well in low fat chocolate milk for PWO. I'll try the chocolate and rocky road flavors in CC next.