Requirements:
CL30
Longsword proficiency
Onehander feat
Insightful strike (INT to damage) Edit: I meant the Combat Insight feat, ahem.
Desired:
High AC unbuffed
Decent BAB (26 would be awesome)
No sneak dice (if at all possible)
Undesired:
Rapier
Armor, beyond light
Anything required in the second hand slot
Yes, I am still trying to get something to emulate the bladesinger class with a real sword, not a poker.