Mane can be as good as suarez if he wants, i doubt it will happen as african players have historically lacked the mental approach to stay at the top level for long periods. Only can think of george weah and drogba.
Mane is an explosive type of player and unlike suarez he is more of a winger style than a striker. If you want to compare him then compare him to neymar, I doubt that he will be as good as neymar however he has similar style to neymar. He might be as good as him though he has the potential to be one