Hi I'm looking into taking up a martial art. I'm looking at Tai Chi Cuan or Hun Gar.?

However I want something that's more 4 a no rules apply/ street fight/ bar fight then a tourment/ show type martial art. I'm also in need of somthing that's easy on the back. (I've got a bad lower back so.....) I know Martial arts isn't about looking 4 a fight/ trouble. I find myself alone alot during the day and night and there's nothing I can do about it. So I'm looking into a real world app. self defence that I can use. I'm hopful about the Chung/ Gar but I'd love any and or all help in this matter. THANKS FOR READING AND HOPFULLY REPLYING =^-^=