Well the thing is he wouldn't be as skilled individually in either of those two aspects.
Nagato had a lifetime of practice with the rinnegan and had Uzumaki chakra reserves. So Madara is definitely at a disadvantage here as he has far less chakra and isn't as skilled with the rinnegan.
As for Itachi, I would say that they would be pretty even except Itachi is likely a little bit more skilled with genjutsu and Madara is probably more skilled with regular ninjutsu. The real thing separating Itachi and Madara is the legendary weapons. Itachi's Susanoo is nearly undefeatable, and he has the Totsuka sword to seal anything it touches.
And contrary to popular belief Susanoo does have legs and is mobile, as seen in the latest chapter.