We've had two Jack Russells. My favorite, a childhood dog, was a little fiesty Jack named Penny (Lane)
She was the BEST dog ever. Jacks tend to be very playful, need lots of attention and affection, and are fearless. She always wanted to play with my brother and I, as well as all our friends. You clearly have a family, so I would think it would be a good breed. I still miss her, and she's been gone for a long time.
She liked toys! In fact, she adored toys, esp. ones that would squeek. She also had a particular interest in socks, and balls of any variety! Both our Jacks loved toys, actually.
Her small size made her very easy to care for. She was behaved on a car trip, and was easy to bring places. We could bathe her in the kitchen sink, pick her up if she was bothering anyone, etc. But she wasn't aware of it. She'd bark at anyone/anything, letting them know who's boss!
Let the pup visit with your children, and see how things go. Have you had dogs before? Do your kids like dogs? Be ready to make a strong commitment. Dogs (or any animal) need a lot of care. I highly recomend a Jack Russell, I know I'll be getting another as soon as my living situations allow it!
But its always worth it!! Good luck in your selection
~Mira