I personally travelled with my two kids, in a truck for 20 months (jusalulu) and can honestly say that it was the best experience ever, both for me my husband and kids!! despite all the unforseable things it was a great experience and we will certainly be repeating it. Don't forget your dreams. For the kids I think it would be hard for them not to enjoy it.....Full exclusive parent time, new stimulus, new friends etc etc. Don't forget there is a traveling community out there, and my kids had a very sociable time, both with locals and non. For your wife of course i can't say, but as a mother (our kids were the same age as yours when we left) I can honestly say that kids are easier traveling than at home....
Financially of course you have to arrange things. We spent (including 2x shipping, airfares, presents, restaurants,medical fees etc.....everything from home to home ) an average of E1600 a month....
My advice is DO IT........You will feel truly alive, and who knows maybe make some life changing decisions. For us this was definately the case.
P:S: Dont worry about the kids education, what they learn in one year traveling will stay with them for the rest of their lives....unlike many things learnt at school (at least in my case!)