I would say Hernandez. He's incredible. Most important stats are positioning, pace, finishing and composure. Decisions is an important stat if you don't want your player to be always found offside (which Hernadez is quite often due to his average decisions stat).
If you want a very cheap option, look for Wilfried from Vitesse. He costs around 3mio and has scored 9 goals and 8 assists in 11 matches for me. He is definitely not the best, but for his price he is fantastic. Eduardo Vargas turns also into a fantastic poacher
Stats wise it's Messi no doubt. But Cavani is one of my favorites. Just signed him for 48M 2nd season and he's scored 7 in 4 preseason match, just played Com Shield against United and he banged 3goals! His pace,movement and finishing is so sick!!