Mustrum_Ridcully said:
Halfling Rogue/Fighter might be a good idea. Two Weapon Fighting is probably a really good idea...
Right. Don't care for the low weapon damage, sneak attack is your friend. PBS, Rapid Shot, the full TWF feat chain... four levels of fighter are enough at first. In that case, I'd even start with fighterlevels for the hitpoints.
Carry lots of hidden knives.
Two possibilities:
Ftr1: Two Weapon Fighting & Weapon Finesse. (You'll be ok at melee).
Ftr1/Rog1: sneak attack +1d6
Ftr2/Rog1: Point Blank Shot & Rapid Shot.
Ftr2/Rog2: Evasion.
Ftr2/Rog3: sneak attack +2d6
Ftr3/Rog3: Weapon Focus knife.
Ftr4/Rog3: Weapon Spec knife
...
Level9 feat: Improved Two Weapon fighting (melee) or Quickdraw (ranged combat) and sneak attack +3d6
Rog1: sneak attack, Two Weapon Fighting.
Rog1/Ftr1: Weapon Finesse
Rest see above
Biggest problem I see: it will be difficult to enchant your knives properly. Flame Arrow is nice for shuriken but not for you. You have to rely on your strength, PBS, sneak attack and Weapon Specialisation damage extras. Perhaps ask your DM for a feat like Natural Knifeman (similar to AU feats).
OTOH: you can always have knives made from different materials, they should probably be cheaper than most other weapons.