Depends on how you want to go about it.
If you're looking for more ab, go halfling. If you want instant detect, go elf.
So for Halfling you'd aim for something rapier based for crits+dmg, maybe 19rogue/7WM/14Sin? or 15/7/18 for an extra feat. Dmg will be about the same.
Maybe start like 10STR/20DEX dump rest into INT
Feats
1:Dodge
3: WF:
6:Mobility
9: Spring
12:Expertise
15:WW
18: Wep finesse
21:Blind fight
24: EWF
27:Eprow
30: ESF disc (can use whatever, it's disc will suck none the less, but this will stop low AB monks from KDing you)
33:Gdex
36: Gdex
39:Blinding speed
Bonus feats at 14/18 sin
14 Gdex
18 Gdex
Something along those lines, pre epic lvling is of your choice. I'd wiggle 4 levels of WM in there for the BAB.
Massive faults: complete crap disc and saves, low AC, slow as hell
Bonus: good flanker, good dmg, can paralyze by rare chance.
Conclusion: Would never fking make it, only usable when in a large scale war and trying to cherry pick or catch a ND runner by chance.