I always tried to combine the work on interesting (and even better on my own) project, and to capitalize on this.
I was never interested in large amounts of money.
I can say that it turned out, several times and with varying degrees of success. And I can do what the findings of these cases, which may be useful in the future.
First, if you managed to establish your own small company for money sponsoring organization, then you should not relax. Financing institution may devour you with your project. In such cases it makes sense to have several organizations concerned with various equity participation.
In general, your own company is a separate conversation.You will not be able to form a small company and develop further in most cases. I'm not a businessman, and therefore can't discuss other ways of creating a company. From the viewpoint of an engineer is better to go a different way. For example, you already have a project that is developed. It's not a secret that the development of the project rather resource-intensive exercise, and intensive development without funding is unlikely. In this case it's necessary to find company, which is interested in such kind of a project. If such company was found, then you hire to work and will assemble a team of specialists. But you shouldn't think then that life was a success, you will have a short time and insatiable wishes of management, and these suggestions will tend to rise.
The deal with the closed project makes no sense in this case - your exciting project will turn into another ugly products, and work on it will be the usual routine. Make your project licensed under free software license (GNU GPL/GNU LGPL), companies offer a product, not a software in most cases. Also, take an existing open and free source code to your project - no one is interested with development all things from scratch.
But don't forget - this symbiosis is not eternal. Ultimately, when your design will come from the door of the research department, the company will not expand the work on your project, instead, your work will be directed to the specific requirements of company management. At this stage it is necessary to separate the project from the company and develop it in an open community of developers. It follows from this - to work on the project is open, and in the broader framework than require your employers.
Well, Jari OS is on this stage now, and I hope that all works on this project will be helpful for community of free software. Also, I will continue works on project with smaller team.
In case of Jari OS, I had a several mistakes: a small open community, not documented internals.