ACN is held every even year between January and February (mainly due to Africa's rainy season in the summer)
Sissoko is also one of my favourite players, but if you look at most of the big teams in the continent, they've all got heavy weight players. Mali many times does well, but they just can't go all the way. To win the ACN you also need a lot of things besides just good players, you need a lot of discipline, mental strength, and experience on the national scene in African football, becuase the environment in Africa is very intimidating. During the ACN many teams just are not disciplined enough and self destruct as a result (e.g. players being sent home early etc.. ) .. Its a bonus too if your team wins the support of the local crowd on a large scale, like Egypt NT in ACN Burkina Faso 1998, Nigeria NT in ACN Egypt 2006, etc..
PS You mean Mali, not Ghana, right?