A JD is usually more versatile than a PhD. I've heard that point argued elsewhere before. But, it really depends on what you want to do with that JD. It sounds like you're leaning toward "advocacy", and I agree with the other comments on this thread that a JD is not strictly necessary if that's what you want.
As for sticking around for an extra year -- really think that through very carefully. Not only are you adding time, you're accruing substantial additional debt, (unless you're fabulously wealthy and don't care).
Finally, I don't believe in the notion that getting any other degrees is necessary in your case. You've already earned a baccalaureate and are working on the post-graduate degree. Unless your intention is to collect degrees like baseball cards, stop there, and focus on your career. Chances are, you already have every thing you need to know, have a good employer who may be willing to help you achieve want you want, and just need to decide in which direction you're going to set out. Tend to that.
And if you have any doubt that I'm right, consider that Focus:HOPE was started by a parish priest and a housewife in the middle of riot-torn Detroit in 1968. Think of what Father Cunningham and Eleanor Josaitis have accomplished. There are no degrees you can earn for that. Its just a lot of hard work.