I'm trying to find out what everything offers, and that's the problem. It's hard to find concrete answers. I visited a Shotokan dojo a couple summers ago and watched a class. It's really difficult to assess an art by short-term observation.
I'm trying to find out what these disciplines offer so I can see what is the best fit for me and also what I can access locally. It's turned into a serious pain in the ***.
Firstly are you sure you need to train martial arts?
It's going to take quite a while to learn any techniques to the point where you can do them instinctively without having to think about it. Have you asked current prison officers what they advise? I know most prison officers here don't have martial arts training, they don't need it. Is it part of the qualifications you need to be eligible for the job? this is what you need to be eligible for the UK job, all sorts of things, there's a physical test, a maths test, eyesight, nationality etc but nothing about being able to do martial arts. This is because you will be taught all the techniques you need and they will be the legal ones which means you will be covered in any enquiry. Prison officers don't work alone, they work in teams, getting on with your fellow officers might be more important than knowing martial arts! Home | NOMS Careers
If you want to train martial arts but don't need to then choose one you will enjoy regardless of whether you think it will be useful for your job, it will be even if you don't think so because of the benefits of training any art.