I hope this helps.
This is a PrC that I found a long time ago. I have never played this class so I can't say if it is balanced, but it looks pretty good. I also can't take credit for it, I don't even remember what web site I found it at.
If your DM will let you play it, it might be just the thing you are looking for.
Since it is so old, it does not have some of the newer feats from the splat books. You should be able to modify it a little with some of the newer feats, if your DM will let you.
Enjoy!
Knife Fighter
The Knife Fighter is the master of the dagger, equally adept at wielding the often underestimated weapon in close combat, and as a lethal thrown weapon. Mobile, calculating, and brutal or elegant, Knife Fighters usually pursue careers as pit fighters, facing other such combatants in ruthless, often illegal bouts, or as skilled enforcers and assassins for certain criminal elements.
Because of the class' typically shadowy background, it is extremely difficult — although not impossible — to obtain Knife Fighter tuition outside of the domain of the criminal underworld. As a result, few individuals, other than Rogues and Fighters, enter this prestige class. Of the various races, Humans are as suited to the class as they are any other, Halflings find themselves to be adept knife-flingers, and Half-Orcs, and other savage humanoids, find the class, and its usual background, suitably violent. Dwarves, Elves, and Gnomes usually view knife fighting as disdainful and distasteful.
Hit Die: d8.
Requirements:
To qualify to become a Knife Fighter, one must fulfill all the following criteria.
Base Attack Bonus: +5.
Feats: Ambidexterity, Dodge, Weapon Focus (dagger).
THE KNIFE FIGHTER
Lvl BAB_F_R_W Special
1st +1 +0 +2 +0 Dual Blade, Point Blank Shot
2nd +2 +0 +3 +0 Versatile Blade, Vicious Strike +d4
3rd +3 +1 +3 +1 Intercepting Blade I, Snatch Blade
4th +4 +1 +4 +1 Dual Throw
5th +5 +1 +4 +1 Back to Sender
6th +6 +2 +5 +2 Inter. Blade II, Vicious Strike +2d4
7th +7 +2 +5 +2 Improved Two-Weapon Fighting
8th +8 +2 +6 +2 —
9th +8 +3 +6 +3 Intercepting Blade III
10th +10 +3 +7 +3 Vicious Strike +3d4
Class Skills:
The Knife Fighter's class skills (and the key ability for each skill) are Bluff (Cha), Craft (Int), Gather Information (Cha), Intimidate (Cha), Knowledge (Streetwise)(Int), Jump (Str), Listen (Wis), Spot (Wis), and Tumble (Dex). See Chapter 4: Skills in the Player's Handbook for skill descriptions.
Skill Points at Each Level: 4 + Int modifier.
Class Features:
All of the following are class features of the Knife Fighter prestige class.
Weapon and Armor Proficiency: Knife Fighters are proficient with daggers. Knife Fighters are proficient with light armor, but no shields. Note that armor check penalties for armor heavier than leather apply to the skills Balance, Climb, Escape Artist, Hide, Jump, Move Silently, Pick Pocket, and Tumble.
Back to Sender: If a Knife Fighter with this extraordinary ability makes a successful Snatch Blade attempt, he may immediately launch the caught projectile back at the attacker who threw it, making a standard attack roll using that weapon. Using this special ability doesn't count as an action. It is not possible to use Back to Sender on a weapon that has been "returned" using this ability, although a weapon thrown using this ability may be caught using Snatch Blade.
Double Throw: A Knife Fighter can throw two daggers simultaneously per attack, providing he has one in each hand. If both are thrown at a single target, make two separate normal attack rolls; if each is thrown at a different target, use standard Two-Weapon Fighting Penalties (taking into account Ambidexterity, Two-Weapon Fighting feat/Dual Blade special ability, etc.)
Dual Blade: When wearing light or no armor, and armed with a pair of daggers, the Knife Fighter can fight as if he had the Two-Weapon Fighting feat. If the Knife Fighter already has the Two-Weapon Fighting feat, he gains the benefits of the Improved Two-Weapon Fighting feat when armed with a pair of dagger, and wearing light or no armor.
Improved Two-Weapon Fighting: When wearing light or no armor, and armed with a pair of daggers, the Knife Fighter can fight as if he had the Improved Two-Weapon Fighting feat. If the character already has this feat, he reduces the penalty to his second attack with the off-hand weapon to -2, when using Improved Two-Weapon Fighting.
Intercepting Blade: The Knife Fighter becomes extremely proficient at using an off-hand dagger as a parrying implement. When armed with a pair of daggers (one in each hand), and wearing light or no armor, the Knife Fighter gets a bonus of +1 to his Armor Class at 3rd level. This bonus increases to +2 at 6th level, and +3 at 9th level. If the Knife Fighter uses the off-hand dagger to attack, he loses the Armor Class bonus for the rest of the round. The Armor Class bonus is an Armor bonus, as the off-hand dagger is essentially being used as a "shield".
Point Blank Shot: The Knife Fighter gets the Point Blank Shot feat for free.
Snatch Blade: The Knife Fighter may snatch small thrown weapons, such as daggers, dart, and rocks, out of the air. He must have at least one hand free (holding nothing) to use this ability. Once per round when he would normally be hit with such a thrown weapon, he may make a Reflex saving throw against a DC of 20 (if the thrown weapon has a magical bonus to attack, the DC increases by that amount). If he succeeds, he catches the weapon. He must be aware of the attack, and not flat-footed. Attempting to snatch a thrown weapon doesn't count as an action.
Versatile Blade: The Knife Fighter learns to make more effective use of the dagger, and may choose to make Slashing or Piercing attacks with it.
Vicious Strike: At 2nd level the Knife Fighter gains the extraordinary ability to inflict grievous wounds with a dagger in melee, gaining a bonus of +1d4 points of damage added to his normal roll. When making a vicious strike, the Knife Fighter cannot attack with a weapon is his other hand, although he can defend with it (and can use the Intercepting Blade special ability). Like critical hits and sneak attacks, Vicious Strike is ineffective against constructs, oozes, undead, and fortified armor. Every four Knife Fighter levels gained thereafter, he increases the damage by +1d4. If the Knife Fighter also has the Rogue's Sneak Attack ability, and utilizes it successfully, the Vicious Strike damage stacks with the Sneak Attack damage.
