The key to your question is, "a good cash flowing business". We have had this question several times, before. The answer is always the same: There is absolutely nothing for a Seller to gain, and much to lose by doing things in this way. As a Broker, I would never, ever counsel a Seller to take such a deal.
Yes, there are plenty of smart, trustworthy people in the market. How do you quantify that? How do you guarantee that? Would you give up something that you worked for, invested in, starved for in come cases, and turn it over to a complete stranger, who tells you he is smart and honest? Would you give up your livelihood for such a move?
The only time I have ever seen anything like this is with an Owner who sells to one of his/her key employees. Then, it is turned over to someone he/she has known for a number of years, knows the employees record of integrity and know-how. Only then does it make any sense, at all.
Is it possible? I would never say never. But as a Business Broker, if the business has a "good cash flow", I would never, every counsel a Seller to take such a deal. There are too many alternatives to get him/her a relatively risk-free deal. If the Owner took a lot of risk, put in a lot of money, time, sweat and sometimes blood to start or buy the Business, why would he/she do the same, in order to sell it, if there were viable options. And if it has "good cash flow", there are always options!
I know that is not what you want to hear, but I don't want you to go around chasing windmills, either. Borrow from friends, family - do whatever you can to put the funds together on your own. But getting it from the Seller in this way is next to impossible - and should be.