Can we pass our business down to our children for free without any tax consequences?
A preliminary problem you have is that, as a sole proprietorship, your husband has no business to transfer. Whether the business goes to your sons or otherwise, if there’s no separate entity, the business cannot legally exist without the owner (in this case, your husband). In addition, whether and how you can ultimately transfer an entity to your children tax-free depends on the form of entity, the (cost) basis in the entity, and your personal tax situation. I would suggest you consult with both an accountant and an attorney who are experienced in succession planning issues.