Aikido or Judo

Hello, Ive just got a job working on the door of a nightclub (in the uk) I appreciate that your words are your best weapon, and that you cant use violence, but as im only slim built, I feel I may need some assistance.

I have been looking at Aikido and Judo, mainly for the defence tactics (the aim not being to hurt the opponent) and other reasons like, pressure points, and stand up grapping, might be useful in removing a heavier stronger person. Which style do you recommend? I know JJJ and BJJ are good, but I would rather learn something that wont get me into trouble! All advice would be great! Thanks!