Firewire "type" help

I was searching for a PCMCIA to firewire for my laptop … I thought it was a simple task until I ran into:

Firewire: 1394, 1394a, 1394b, 1394-1995…4 pins, 6 pins ???

What the heck?? anyone knows the difference and which should I go for for optimal speed? I’ll be using it to hook up my external enclosure with a dvd burner. Thanks.

I just got the plain vanilla CompUSA 1394 card and it works fine for me.

1394 is just the numbering convention for FireWire interface, 1995 is when FireWire received the IEEE certification. 1394a = 400 Mbps and 1394b = 800 Mbps. Add-on cards for 1394a is PCI and for 1394b is PCI-X (needs higher bandwidth). The 4-pin is typical for digital camcorders or home recording units; aka Sony’s iLink. The 6-pin is more widespread among computer motherboards and peripherals.