Well I would say try Muay Thai. It's the art of 8 limbs for a reason it's pretty damaging also.
Measurement of the amount force, speed, and ratio of force to velocity generated from Taekwondo, Capoeira, MMA, and Karate in this video, shows the taekwondo kick had the most force and speed, but Capoeira had the highest ratio of force to velocity.
Of course it always depends on the person doing the kicking, but I think taekwondo prioritizes increasing the force and speed of kicks, which gives them higher results in that area.
There are other videos to look at too.
Or.....and this just a thought, you could go and train MMA. There are these gyms that specifically train MMA. It's kind of a new thing. Pretty cool actually. Maybe try that one?
What style will teach you the best and most powerful kicks that will hurt somebody for self defence or trainig to be an mma (which is my case) muay thai kickboxing or teakwondo
