2/4 - AKo in BB deep - two-part question

Pre-flop: (6 players) Hero is BB with A K
UTG raises to $14, UTG+1 folds, CO calls, Button calls, SB calls, Hero raises to $80, UTG calls, CO calls, Button calls, SB calls.

Flop: A J 4 ($400, 5 players)
SB checks, Hero...