Hi, lordvader. I recommend replacing the Sorbothane pads with original 1/2" Tenderfoot isolation feet (12.8mm tall). These will do as well or better than 5/8" grungebuster Balls, which are the same height as our regular Tenderfeet and just a hair under 16mm tall. Though not featured on our website, you can order regular Tenderfeet and then mention in the "comments" section of the order form that you want 1/2" tall Tenderfeet instead.
IsoBalls would do very well under the base too, but I don't see that you would need to build up so much of a totem pole. I recommend using four 1" diameter Extra-Thick grungebuster Dots under the acrylic base.
Steve
Herbie's Audio Lab