We have a living room and guest room adjacent to our kitchen. I want to install a sliding barn door on the opening to make it more private when we have guests. The door will slide left to right. The hardware needs to installed along the top of the wall, but there isn't enough clearance to the far left, so I think the best solution is to frame out the opening to 1)make the opening smaller 2) install a header so there is enough clearance along the top to install the hardware. I've attached a diagram of how I intend to frame it. The opening will be about 6 feet wide when I am done.

Do I need a special header to support the weight of the barn door? Can I put two 2X3's together for my header or do I need something more heavy-duty? Also, if you have other suggestions on a better way to do this, let me know. Thanks!

Here is a picture of the current opening:

Here is a diagram of the framing I plan to use:

Example of what I want: