Wait at least a month before putting a cover on a freshly painted car. That being said, the best indoor cover is an outdoor cover. I got into the habit of putting an old throw rug over the nose of the hood especially in the garage. That seems to be a "target area". As to a brand, I like Covercraft. Most Mustang parts sellers carry them in sizes for all Mustangs body styles and years. Figure on paying $265 (NPD price). You will need to "punch" a hole for the antenna, and most covers come with a plastic grommet.
Jim