Master Samurai
I would multi class with Master Samurai. Take five levels in fighter so you can get Focus, Specialization, Power Attack, Cleave, Expertise. Then go into Master Samurai, take the feats quick draw and improved initialtive. You gain great cleave for taking a level in it, plus you get supreme cleave and you even get blades of death which allows you to use twice your strength modifier on attacks with a katana, plus a host of other good abilities, but once you get past fourth level its all filler abities that you could do without. Now once your done with 4 levels in that finish out Iajutsu Master and take the last level in fighter. If you decide to go non human then drop expertise till later.
1.F1 Weapon focus, Power Attack
2.F2 Cleave
3.F3 Expertise
4.F4 Weapon Specialization
5.F5
6.MS1 Quick draw
7.MS2
8.MS3
9.MS4 Improve Initiative
10.IAJ1
11.IAJ2
12.IAJ3 Improved Critical
13.IAJ4 Combat Reflexes
14.IAJ5
15.IAJ6 Dodge
16.IAJ7
17.IAJ8
18.IAJ9 Mobility ,Spring Attack
19.IAJ10
20.F6 Whirlwind attack
Once you meat the requirements the feats can be anything you really want, I just put in my suggestions. The Master Samurai can be found in Sword and Fist Pg. 29. I hope i helped! ^_^
