You have so many great options, you honestly can't go wrong. Every discipline will improve you as a person, the real question you should ask is, What are you looking to improve? Jui Jitsu is great and definately a good workout, but it's not exactly geared towards getting you in better shape. The striking arts as well as wrestling, I find to be the greatest workout. You should take Jui Jitsu since it's close by, (you will be more inclined to actually go) and you should jog there to warmup.(if it's within a mile or two), and do yourself a favor and get a punching bag. If you like Jui jitsu, It will give you a thirst for all of the combative arts, and from there getting in shape will be an afterthought.