Hello,
I am an engineer and I can help you. If you want I can even build you a prototype before you hire me.
I propose you the following. I create the chrome extension, you provide me with a rtmp server. I stream to it with my extension : if you are satisfied, you hire me and get the solution. If not, you can still hire another freelancer to get the job done.
If I understand well, all you need as an interface is a form where you put the rtmp data, and a start/stop button to stream.
I hope we can work together. Please send me a message if you are interested.
Best regards.