I'm sure that someone will correct me if I am wrong...
3 options: (or hybrids of each)
(A) 2 EtherDongles and 8 16-port active hubs.
-- this is treated as 2 devices in Vixen/LSP, and each has its own 1-4096 addressing. each etherdongle has a separate IP address and therefore is independent of the other etherdongle.
(B) 8 USB dongles and 2 combiners, and 8 16-port active hubs.
-- this is treated as 8 devices, but each group of 4 dongles can be combined into a single cable run to take you to the first active hub. Each usb dongle would have addressing of 1-1024.
(C) 8 USB dongles and 8 16-port active hubs.
-- this is treated as 8 devices, each usb dongle would have addressing of 1-1024.
The EtherDongle is available from a coopbut that coop closed already.