Sounds like you should sell the product to someone that wants to do the business side of things, and stay on as the head of product development. It is doubtful

Sounds like you should sell the product to someone that wants to do the business side of things, and stay on as the head of product development. It is doubtful to me that open sourcing it will make it well known unless it is a technical product and your customers are developers. Do your customers care if it is open source? Most people selling Asterisk installations never explained to the customers that technically the software was free. All that will be accomplished is that someone who likes marketing & PR can pickup your work and create competitor D, that has everything you have, but with someone that likes to sell. Better to get that person on your team after they pay you some money.