stealing than hit weak ace

[Paul2432]

This hand occurred in the 2/4 NL game on Stars

UTG posts $4BB+$2SB and checks. I raise to $16 with Ac7c to try and steal the larger pot. Everyone folds but the poster. Flop comes Qc 8d 8c giving me a flush draw. Opponent checks and I bet $30 to follow through.

Opponent calls. Turn is an ace and opponent leads out for $100. We both started the hand with about $400. What is my best play here?

Suppose I call, and the river is a blank. Opponent bets $200.

Paul