Unearthed Arcana?
This is going to sound like an odd suggestion but since its open to you?
Why not play the generic warrior from the UA, for the sake of argument.
Warrior20 *Samurai*
Human (bonus skills!) Skills, Hide,Move Silently, Concentration, Diplomacy, Umd, Spot, Spell craft
Human Feat Improved initiative
1st. Combat reflexes. Bonus Feat: Sneak Attack 2d6 (Aka Iujustu focus)
2nd. dodge
3rd. Combat expertise
4th. Karmic strike
5th
6th Power Attack, Leap attack
7th
8th Improved bullrush
9th Shock trooper
10h Evasion
11
12 Improved sneak attack, MageSlayer
13
14 Pierce Magical something.
15 Greater sneak attack
16 Favored enemy
17
18 Favored enemy
19
20 Favored enemy!
Generic classes SRDNah I"m just kidding.
I suggest a duskblade. You don't ever even have to use a spell burn all your spells if youlike into "Chi" strikes using arcane strike
If you absolutely must have diplomacy then dip one level of Something for it. Hexblade maybe.
That or play a full hexblade, its not bad its the master debuffer actually. Which can be pretty good.Dictuum made a handbook for both...