not to rain on your parade, but if you are going to be selling something to a bunch of people, you really should be totally familiar with its operation in case problems arise, or you'll have some unhappy customers. If someone else does the design work for you, you aren't going to have that kind of understanding. Nobody understands the workings of a microcontroller project as well as the person who spent countless hours tearing their hair out in frustration while writing the code. Perhaps you should try to go to market with a product that you have the knowledge to design by yourself, and maybe work your way up in the future.