I am going to chime in with some thoughts (which often differ from my comrads, though I do always respect their opinions - except on ice makers, but that is another story) ...
If you want to live aboard - GO FOR IT. Get excited. Make it happen. Take the family... I did. They were some of our best times, and worst times. It was everything we thought it would be, and a whole lot we did not think it would be. THere are beautiful sunsets. Awesome people. Hop in the dink and stroll through the marina. Take the kids out fishing. Drop the lines and go anchor off some distant island. And everytime you think to yourself, "Man, a boat sure is expensive..." just stand up in your cockpit and admire your back yard. Depending on your level of adventure, it may never be the same.
I will make the same assumption my fellow sailors did on your boating experience: little. Living aboard is NOTHING like living on land. Don't believe me? Drive out to the marina the next time a storm blows through. Walk on that boat (even the one you chose) and ask yourself, "Hmm, now where do I wash clothes?" The marina laundromat... which can be an adventure in itself. You think living in a house is expensive, well, a long time ago sailors changed the name of vessels to: Bust Out Another Thousand... which we commonly call BOAT today (haha, made that up a little). Everyone makes fun at me for this one (especially SD), but where are you going to get your ice??? Most boats (except mine, of course!!!) do not have an ice maker. Forget those little trays, they are a piece of junk. Water is limited. A system failure on a boat can be serious and requires immediate attention. Oh, and (duh), did I mention that they CAN sink?? And since you have kids, let me ask you where are they going to play? Where are they going to ride their bikes?
I am not trying to scare you, at all. In fact, I hope that you do it because it will form the basis of the best years of your (and your families) lives. However, there are huge adjustments and costs. Just be aware of it.
As far as boats go, here is my humble suggestion - which is often critiqued and dissagreed with by many other sailors, but that is nothing unusual: buy a newer production boat (Catalina, Beneteau, Jeauneau) that is big, fat and roomy versus a older, "bluewater" (whatever that means... again, another story), narrow beam boat. Catalina especially is a well made boat, has a faithful following and awesome owners group, and is fat and comfortable (Frank Butler probably would die if he heard me say that). It is NOT as well made as many of the other offshore boats, but it is not designed to circumnavigate... instead to be a comfortable coastal cruiser. It is also a lot less expensive for comparable year. However, I will say that I have had my Catalinas out in weather that would be tough to swallow for ANY boat and I am still here to tell about it (though my stomach lining is floating out there somewhere).
Do it. Make it happen. It is awesome and great and worth the frustrations you WILL encounter. My kids love it and it has made a big impact on them.