Hi,
Please check out the KB below. With this .exe you can calculate your bandwidth limitation for the Imaq IEEE 1394 driver
http://digital.ni.com/public.nsf/websearch/04E0D6266317021C86256D52005D4F3B?OpenDocument
If you cannot reach your specs with a CVS than, indeed, a Firewire card with multiple inputs can be a solution.
Regards.
JorisV
AE Belgium