A long time ago I bought from Blinds.com
I couldn't find a large enough blind for my sliding glass door at Lowes and HomeDepot, so I checked out their website. Their shades were cheaper and were available in my size. When it came, the bracket was the correctr size, as were the vertical blind strips. Unfortunately, the color was so ugly, that I didn't hang it up.
I went with a curtain.
I recently looked at their website again, and the prices seem higher, but their return policy seem more generous.