IEEE1394 (firewire) for both deck control and A/V input stream.
Thank you JoeBloe & John. Appreciate the quick response. The link to the firewire issue was also great.
It is just getting a bit scary when I look at the 'final' price of the system I will need to get to run this . . .
A good FW-400 (IEEE-1394a) PCI card is about US $ 10 - 20, so that is not too big an investment.