Hello!
I'm a game developer who works primarily with Unity, and I've spent many hours with the new Unity UI system. It won't be a problem for me to hook up a lightweight UI manager to handle the canvas in your game. The 3-day estimate is just in case I have any additional questions for you. I don't imagine the work taking 3 days to finish though; this should be quick.
My scripts will be well-documented and efficient, and functions will be aptly named for good coding standards.
Let me know if you're interested, and we can discuss the project in greater detail!
Thanks,
Dustin Peerce