Here is a template to work with:
http://nwn2db.com/build/?263197
You mentioned you want to use a light shield, but, you'll get more damage out of TWF. Though, you can pop a shield into your off-hand when you need it (and there are some nice shields out there that will help your toon's experience out, greatly, like a shield with high Spell Resistance, which can disable a caster mob, when needed).
Any Feinter build
requires you to be savvy and collect gear with Bluff bonuses. It isn't the easiest of tasks, but also not impossible. As Dizzy D said, you need to understand that mobs get a d20 + Base Attack Bonus + Spot skill check against your Bluff score. So, if a mob or other PC has 30 BAB and 33 Spot, your PC would need 83 Bluff points in order to 100% Feint sneak attack! That ain't no joke. Luckily, its much, much easier than this, with mobs, at least.
And, if you are Feinter, you'll really be a good friend to other PCs in a group, because when you successfully Feint, they also get to use their Sneak Attacks. Win Win!
Oh, btw...you can make this build even more Charismatic if you lower other Abilities. If that is your RP. But, wearing a +3 CHA item the build has a 16 CHA, which in D&D terms, is: "Popular, receives greetings and conversations on the street"