This guy is 19/3 over 800+ hands and will not stack off easily. I finally have him where I want him here, how to best extract value?

Full Tilt Poker - No Limit Holdem Ring game - Blinds: $0.50/$1 - 8 players - Converter

Stack sizes:
UTG: $189.70
UTG+1: $63.20
MP1: $115
MP2: $98
Hero: $125.55
Button: $98.50
SB: $120.80
BB: $100

Pre-flop: (8 players) Hero is CO with 4 4
4 folds, Hero raises to $4, Button folds, SB calls, BB folds.

Flop: T 4 8 ($9, 2 players)
SB checks, Hero bets $7, SB raises to $18, Hero ???