Hi Sara, you could build a large elongated open top wood box about 16" tall" X 24' deep x 48" long. Then build a wood cart with wheels to set it on the height you want.
Set the box or attach it to the rolling wood cart.
Then install wood cubbies or PVC cubbies so the glass stands upright in the box.
You can easily see every color in the sunlight, you can move the cart around at will, easily open and close the windows and not have much if any of the window blocked.
It would hold a ton of glass.
