I'd say Kirin personally since Kirin Sasuke can be anyway in the map to hit his ougi if set up with a support that puts the opponent in standing hitstun for a while while Taka Sasuke needs to be albeit mid range to hit it, I've had situations where Taka Sasuke's ougi completely whiffed up close, and besides, Kirin comes out faster IIRC.
Also Kirin Sasuke has Fireballs so he can play a long range game as well which makes him versatile while Taka on the other hand only has Chidori.
When you TK Kirin Sasuke's j.O and they block it, you can mash out a grab right away right when you land to grab them and they can't escape it, Taka Sasuke's grab takes a bit longer to come out IIRC, but don't take my word for it.
At the end of the day it's up to personal preference, if CC2 was generous enough to change costumes then I'd be using Kirin Sasuke with the Akatsuki cloak all the time.
http://www.youtube.com/chaos1778 Currently playing: Final Fantasy XIII, Metal Gear Solid: Peace Walker, BlazBlue: Continuum Shift, and Persona 3 Portable
Kirin Sasuke can be tricky with his ultimate jutsu and his fireball ninjutsu (charge-up) isn't too easy to dodge either. He's pretty good all-round but I personally prefer taka sasuke. Once I got used to using his tilt+circle attack to push enemies away it just grants so many more opportunities. tilt+circle = chidori/support attacks/grab. Not to forget the long-range grab (Y). And he generally just looks awesome with the Akatsuki Robe xD