Hey, man, I'm in the same position as you. If you look up some of my threads, that's all I'm interested in - Fitness and Defense.
But yeah, I'd stick to a combination of boxing, jiu-jitsu, muay thai, and krav maga. I take the first three (new to them though), and will start on Krav Maga after I get better at the other three.
And I don't know much about JKD, but from the videos I've seen, I don't think it's too great. Also, I think it's more of a concept than a style. So if you take multiple arts, you're basically practicing JKD. :-\
Good luck in your training.