I would say the Ko, main reason is for the time it will last compared to a Koxx. Only problem about the Ko is that the brake mounts are welded to high up so you have to have your wheel all the way forward to get a square brake set up
It will be your forks that are making the extra lenght, if you look on tarty's you will see it says measured with Echo etc forks. Your forks might be diffrent geo making the bike longer.