Any OHCI complient card will do. Look at the Linux IEEE 1394 Hardware Compatibility List if you are unsure.
For your iPod the bus needs power, the old cards have a power connector for that, newer cards take the power from the PCI bus, so you can't be sure about that. Look at the package/website and search for: 'providing bus power', 'cable power source' or similar ...
Beware: D-Link DFW-500 may not always work. (reported by rob)
I have a Billionton card and a noname card with a Lucent chip.