Ok, I am biased. I really like Headhunter Blades, and specifically, the Rat Training Package which I have reviewed in the past. I've been eyeing the Kryptos Training Package by Tuhon Harley Elmore of Headhunter and finally bit the bullet and purchased one.
The training package comes with a training knife that is designed to be 1/2" shorter than the live blade so that when you practice with it you are imprinting an automatic 1/2" penetration.
The knife is 10" long and remarkably comfortable to wear in spite of its size.
The handle is designed to increase friction closer to the blade, thus making it easier to grasp so that your hand will not slide up onto the blade.