PCMCIA 1394/USB2.0 combo card video IN & OUT

I want to buy a combo FireWire & USB 2.0 PCMCIA card for
my 2.4 Celeron notebook. I want to use this card for editing
video. Please tell me if this will exceed maximum PCMCIA
bandwidth or violate XP operating system limitations.

The plan:

Plug an external 7200 RPM hard drive into the PCMCIA USB 2.0 port.
Designate this *external* hard drive as the video capture drive.
Simultaneously plug in my digital camcorder into the same PCMCIA
card's 1394 FireWire port and tell the capture program to start
capturing video.

Anybody try this before? Any advice appreciated.