Which martial art for the youngins'?

Well, a comment I just left on Stephen's site, Standing Outside Looking In, got me to thinkin'. What martial arts form is best for my girls to learn? At the risk of sounding plumb crazy, I really do want them to learn how to tear an attacker apart. And...at the risk of hurting feelings out there, most of the forms seem too much like a show or too specific to me. I've spent some time watching the Gracies on Youtube destroying any takers. That includes karate, tae kwon do, kempo, and on down the line. It seems Brazilian jiujitsu is the way to go with a little Krav Maga thrown in. I have downloaded the USMC's combat martial arts program and am reading it, but am no instructor by far. I will say I have watched some video of it in action as well, and I like the fact that these guys are looking to kill or maim their enemy.  I spent six years as a wrestler in high school, have had some training, and am firmly convinced, one on one, that if I can get most zombies on the ground I can do some serious harm( I don't plan on fighting fair). That seems to be the basic idea of the Gracie style. I'm not really sure what to do, because as a thirty something guy I have no problems with really hurting someone if need be to protect the family, but how and what do I use to train my girls?  So...here's the hunnert dollar question-What style do you suggest? Thanks for your time and y'all have a good 'un.