When he was playing for Arsenal, Adebayor was a beast. He's done shit with City, but I believe this guy still has it. His wage his big, but if he comes for free, then it should be ok. If he finds his old form back, Addebayor can become the best strikers in Serie A.
As far as sissoko, I really don't want him to go. Poulsen and Tiago should be sold way before him.