For me it would have to be Mbeng Niang, I'm 8 seasons in and he's at Chelsea leading the frontline with Lukaku and they are really pushing me for the league this year, 1st time in 3 seasons I've been challenged, so far we've both played 21, Won 19, I've drawn 1 and they've lost 2.
If you feel Cavani can hold the front line and keep you heading in the right direction get Niang, he's young and you won't have to go looking for a new striker in 2-3 years, he will serve you well for years.