A couple of thoughts come to my mind:
1. I wouldn't want to rely on a start-up own business for my sole means of support unless I had a LOT of money in the bank to live off of while it was starting up.
2. Would you be willing to get a job to provide a stable, predictable income and health care benefits?
3. Would DH consider finding another job for a while and additionally being a consultant in his field? That way he would have the security of a job and have the opportunity to see if the consulting side takes off and could build slowly, but surely, into his full-time job?
4. Are you and your children prepared to provide the support it takes to start a business?
In reference to my #1 & #2 above - When DH & I married, he was a realtor working on commission. I am a nurse. Realtors working on commission are very similar to being self-employed. Income depended on how many transactions he was involved in and transactions were dependent upon the real estate market, mortgages and a myriad of other things over which he basically has no control.

Also, healthcare benefits were not provided by his broker at a reasonable cost...you could get in on the group rate through the company, but it was not cheap because it was a relatively small group. I had a predictable weekly income and we got our health care benefits through my job @ a much more reasonable rate because I worked for a MUCH bigger entity than he did. We basically lived off my income and banked his commission checks when he got them. My point being that one of you should have a predictable income IMHO.
In reference to #4 above- You and your children have to be on board to support this effort, because it will be a family effort.
We have a friend who has been in the car business, in various capacities, for many years, always working for someone else. He decided to open his own used car dealership. His wife told him she would be on board, support him 100%, knew that it would take a number of years to establish the business etc. So off he goes, opens the dealership and within 3 months she's complaining that he hasn't brought home a paycheck, what's going on, she's sick of working and thought that when he started his own business she could stop working.
You see, his father had built up a very successful car dealership and made quite a bit of money from it. He sold it many years ago, before any of the kids would have been able to take it over. I think my friend's wife thought that he'd be making that kind of money in 3 months and she would be living like Mrs. Gotrocks. What she failed to realize is that my friend's father worked very hard for many
years to be that successful, and my friend's mother and the rest oif the kids sacrificed quite a bit along the way. Well, needless to say she complained so much all the time that he decided to close up shop. And he was actually doing OK for a start-up business...he was selling cars fairly regularly. But she had this impression that he was going to be RAKING IN money from Day 1. She had the impression that she'd be living a certain lifestyle and it was happening quickly enough for her.
Perhaps he should talk to an attorney or someone who could advise him? Maybe there's a way to start small and build up to something bigger?