You can get the parts needed for an upgrade to either the HW-19 Mk3 or Mk4 directly from VPI, or from a VPI dealer. The upgrade will include the laminated acrylic/steel plate plinth, 4 spring suspension units, the heavier acrylic platter, and the spindle/thrust bearing needed for the heavier platter.
I think there is an ad currently running here on A-gon for the parts needed to upgrade to the Mk3 version. I have had the Mk3 version, which I eventually upgraded to Mk4, and there was an audible improvement. The VPI HW-19 Mk4 turntable is one of the real bargains in high end analog playback -- a LOT of turntable for the money. Personally, I would pick the HW-19 Mk4 over the Aries Scout.