I just looked over FRCS's feats and PrCs and hoo boy, it's casters' game.

Anyhow, if you want TWF Fighter (the class), you can go with Cog's suggestion (pretty stylish), or pick up a pair of kukris, grab Weapon Focus line and Imp. Critical along with TWF line. Either case, you want to keep str as high as you can while qualifying for TWF feats (GTW is probably not worth it).

A double weapon with above feats might work too (for a given definition of "work"), using PA two-handed when limited to one action.

Barbarian dip is nifty for Rage, either early game when it's relatively bigger boost or later after you've exhausted the good fighter feats.