skcreidc - great post.

My Heeler mix is a fantastic hiking partner, but I wouldn't feel comfortable having her around kids. Too nervy. That'd also be something to watch out for with Border Collies. Not to say they can't be good with kids, but you'd have to be extra picky. It might be a little counter-intuitive, but if you do decide to get a BC puppy, I'd suggest looking for a breeder of working stockdogs. They put a lot of emphasis on biddability and calmness when not working.

Another breed you might consider (and might not, of course, many people wouldn't) is the pit bull. Again, you have to be choosy, but given the state of the average animal shelter, you'll have a lot to choose from . Take a look at BADRAP if you're at all interested.