I agree with JoeTown.
You really need work toward your goal of touring. This is not going to happen overnight, but it WILL HAPPEN! I really admire your ambition, and I can tell that you have put much thought into this, and you're ready to pull the trigger. First, get yourself, and the family in good biking shape - then do the tour. Then, while in the midst, come back here to post your touring stories!!!!!
As stated, your first goal must be to get in good cycling shape. There are many resources (including this site) that will help you get there.
Good luck!!!!!!