When Personal Projects Start To Conflict w/ Work?

Yhcrana asks: "I am preparing to start a project at the company I work and I have hit a small snag. Over the past 6 months I have been developing a product in my spare time for commercial use and it is nearing completion. The problem is that one of the clients they work for wants the EXACT product I am producing in my spare time. I have held this product from their knowledge on purpose since I was going to be first to market on it. I am about 50 hours away from completion of the project and they now want me to produce the EXACT same thing for them. My question is what should I do? If I complete this product on their time they will want to have some sort of part of the licensing and this is my idea." Similar to an older Ask Slashdot this question approaches the issue from the opposite direction, that of dealing with your job while still trying to complete something you've been working on that may mean a lot to you. What would be the best way for Yhcrana to not only finish his project and retain the rights, but to help his firm's clients as well?

"This product was going to support me in my down time between jobs as I have a couple of clients who are eagerly awaiting its completion and it would net me a good profit just from these clients. I am completely unwilling to just give this hard work to the company I work for.

I want to complete this project, but my working on this product while on company time would probably cause some sort of problem within the company. I have had the idea of perhaps signing some contract with them which lets them know that even though I am completing the product for their client I own all rights to the product. Perhaps offering them a small discount on licensing on the product equal to the amount they paid me for working on it on their time."