Quote Originally Posted by Anxe View Post
Tempest is the PrC for Two Weapon Fighting, I'd go with that.
Much of Tempest is wasted if you're not using two different weapons. (for example, a dervish weilding two scimitars wastes much of the potential of the tempest class.) I'm not a huge fan of the class, really.

Scout and Ranger stack up really nicely if you use the feat that lets them stack for skirmish and favored enemy progression. Of course, scout isn't a Prc.