I am in the process of building my 28'x32'x9' shop. I am planning on using a sliding door, which will be 10' wide by 8' high.

I've seen a few slide tracks for sale on the internet, not sure of the measuements of the brackets holding the track to the shop.

The attached image shows the door opening. How do I frame out the ruff opening, as far as sealing out rain/wind? If the track is suppose to be installed on the lower 2x6, above the opening, do I need to add another 2x6 below this one for the door to butt up against?

Any suggestion?