Motherless thiefling for an additional attack(bite) per round.
Ability scores with racials:
STR 19 DEX 16 CON 12 INT 10 WIS 14 CHA 7
Skills: Trickery(to level quickly with the skill user only gets xp option), Perception
Levels: 17 Fighter, 1 Vivi, 1 Rogue and 1 Barb

Feats: General dual wielder feats, feats that maxes perception and trickery.

drop the dex, swap fighter with ranger(or freebooter) and it'll be fine. Trying both get 19 dex for the twf and high str will bring you nowhere. if you want str dw go for any ranger you fancy.

Only need 16 DEX not 19, Belts and DEX buffs lets you take the dual wield feats so feeling fighter would be better than the weaker ranger option with much less feats no?

ranger has a lot more DPS than fighter, but less AC. Also items counting towards feats is a bug, and might get fixed(probably not). With said bug in mind I guess you could do 11 or 13 dex fighter