no Sasuke's susanoo is the same as Madara's, the fact that Madara's susanoo looks bigger is because Sasuke covered Naruto's kyuubi while both its hands and legs on the ground, as for Madara then he covered him while standing that's why Madara's susanoo looks taller.
if Sasuke were to make the susanoo/kyuubi form stand than it will be exactly like Madara's and also Sasuke jsut made the PS the same size of the kyuubi so it can fit, can't you see while Sasuke was battling the 4 kages his susanoo was only human length it only covered him.
as for the meteorite then they are bigger than the one's edo Madara was using because he wasn't able to bring big meteorites (after Madara got revived he was able to use jutsu's that he couldn't use while in edo mode even Hashirama said that he got his powers back) , but now that he got the the tentails and was revived he was able to bring the big ones which are bigger than any susanoo even Madara's ( as stated above with the images Naruto himself said they are bigger ).
about the dark kurama:
i haven't seen in the manga that it is smaller in size than kurama, it's the same size but its dark and the other one's light,
the only thing it lacks is the other one's chakra.
