For unarmed rogues, there are IMO two builds really worth looking at. 19/1 for the maximum punch and vorpal or 13r/6m + 1 fighter/ranger/monk for more feats (more TR-friendly) and better stunning fist.
[EDIT]
And if you go unarmed - take Bluff. Just do it. If you go anything else, take it either. Stunning Fist + Bluff feels like Rad II Weapons on steroids![]()