Traction control on a 600 isn't needed. I also don't think ABS that's available on any 600 class bike out there would stay on any bike I owned. Even the brand new R6 TC/ABS is admittedly not as advanced as it is on the R1 and I would remove it. They don't have the 6 axis thingy for lean angle, etc.
With that said, the 13+ zx6r is the better track machine of the 2 choices you gave. More people are tracking/racing them which means parts are easier to get, setup info is easier to get, etc. And they do make pretty good power and all.