Plastic sliders worked perfectly, and at a cost of only 8 dollars. For anyone with the same idea, I'd recommend using somewhat larger spike floor protectors as they are prone to tilt on the soft side of the slider if too small. I used the floor spike protectors from an old equipment rack instead of the Wilson supplied larger ones, and nearly impaled my hand. If you let the weight of the cabinet settle them in for a minute or two before trying to relocate the speakers, you'll be fine.
Wish I could add photos to better explain this.
Wish I could add photos to better explain this.