Another idea would be to simply find some nice clear plastic bags
to hang over your unit. They come in so many sizes, so unless you want them specific to your purpose, that would be a less expensive way to go.
What about those bags they put around gift baskets? Nice, shiny, and clear. Would that work? You could go to a store that makes gift baskets, take your measurements in to them and ask if you could buy a couple of them.