Suggestions on a style to begin training.

I'm more interested in self defense than i am in conditioning. If one of the elders could help me out with some knowledge i would be grateful . I'de like to begin training in a style that

1. maximizes (control of opponent, potential non lethal incapacitation, and lethality) but minimizes the amount of stress my ailing joints and slow musles have to take on. basically a highly economy of energy martial art.



2. (this may require a different style training).. has techniques from the outside that focus on defensiveness and personal safety then using a strike to distract disorient or throw of balance the opponent for a high intensity short duration flurry from the inside.



at this point i'm looking into

aikijutsu and ninpo to fulfill number one maybe juijitsu but i prefer to stand.

and

for number two i'm thinking

western style boxing, savate, bartitsu if thats a real thing , also hoping there is a kung fu style . and what about SPEAR and those military styles...



I'm looking to narrow my scope and start looking for teachers.