the HVX wont support captioning, but i believe any of the Sony DSR VTRs or Panasonic DVCPro decks will accept captioning over firewire. We’re using a DSR-25 and DSR-1500A printing to tape with a CC embedded DV file from Macaption.
I use our G5s as loading machines at our place. Load DV / DVCPRO50 via AJAio, and bring those in via shared storage. on some Ive put a couple of hard drives in there and made them a file server.