The martial art you should take should be taught as a self-defense system and not a sporting system. I would also probably take something that trains hand weapons from the same perspective of self-defense. The weapons should be similar to what you may have laying around which basically means knives, sticks, and staffs. To be honest you really don't need to talk a Martial Arts class if you are specifically looking for self-defense training. You will be better at self-defense if you train in a martial art setting than you would be if you took a 3 week self-defense course due to the training of hitting and kicking effectively. But beyond that, much of the self-defense work is preventive measures that help to make you less of a target.
The problem with martial arts is that it takes time to learn how to use the techniques. TKD will probably be easier to learn than Wing Chun, but Wing Chun will give you more options provided that you stay in the Wing Chun school long enough to learn how to apply the techniques. To give you an idea of the challenge, I take a MA called Jow Ga. The techniques that I can use to fight with are the basics. I know intermediate and advanced techniques. I understand the applications of them, but getting to the point where I can actually use them is years away. This is how MA is for most people. Students often fall back to the basics so don't expect to take 5 years of MA and expect that you'll look like the Martial Arts movies because you won't. Around year 3 you'll probably just begin to understand the many applications from the basic techniques.
You're money would probably be spent on something that teaches self-defense and has a lot of street assault type scenarios. I will caution you though. There's a bunch of nonsense self-defense schools and classes out there so be sure to do your homework.
