Up for sale is a solid Oak homemade adjustable book/magazine holder. The overall length is a little over 16" so the actual width available for your media is ~15". The ends are about 8.5" wide and 10" tall. It's high quality (I made it myself) and in great shape, just don't need it anymore and it's been stored in a closet for almost 15 years.
If this piece isn’t exactly what you’re looking for then please check out https://webers-woodworking.com to have a custom piece made.