Need an independent Dog

My family would like to adopt a dog but both my wife and I work. Can you suggest a breed that will cope better with being crated for 5-7 hours during the day. I should also mention that we would prefer a small or medium size dog that is good with kids (ages 7,7 & 12) and other pets (1 Cat). We can give the dog lots of love and attention when home but don't want him to suffer when we are not there. Thanks for your thoughts!

First: For heaven's sake, train the dog to behave so you won't have to crate him at all! A crate is for a refuge, not a daily confinement room!(We both work. My dog is at home for 10 hrs, with a visit from the dog walker, & he's never crated. He does fine.) I can't stand crating, it's boring for the dog & isn't fair to him. Five or seven hours is easy for a well-adjusted dog to handle, especially since you have a cat, too. Cats are company for dogs.
   
If you feel you must contain the dog when you're gone, do it in a room rather than a box.
   
Go to Petfinder & find the local adoption group. Talk to them at their next adoption event. Tell them your situation, the kids, the cats, the size you want. They're bound to have an already-trained dog who was given up by someone who lost their house, that won't need crating at all. There's a lot of perfectly normal house pets out there that need a new place to live.