I'd prefer them to be in a light color to prevent any possibility of color transfer. So that patterned one on ebay isn't one I'd buy. It's cute though.
As far as the ones with the little window, you can get the plastic part at a craft store and just sew it on the side of a dust bag you'd make. It'd be time consuming to cut the pieces and the trim (and have to find the right thread and needle to go through it), but it's possible. I kinda want to make them, you can coordinate the trim to the bag you're storing inside as well.
Luckily for me, my bags have a dust bag or are in use. So it's a project I can hold off on.