when i got my second generation ipod (runs on firewire 400 just like yours) i got myself a firewire 400 - firewire 800 cable, so that way i could plug the ipod into my firewire 800 port on my 2012 macbook pro. it synced without trouble, though it did take about a minute for itunes to recognize it.
Old iPods and new versions of iTunes are one of the best examples of backwards-compatability out there. I still regularly use my third-generation iPod, and it works perfectly with iTunes 11 and Mountain Lion. It even shows the proper icon for the iPod and its connection method