One thing to consider is the amount of data you'll be sending through these ports. If you get the PCI card, each device you connect will get a shot at the PCI bus. However, if you decide to go with the hub, each device will connect to the hub and eventually end up sharing the bandwidth of the one USB port the hub is connected to. Now, if all you'll be connecting to the hub is keyboards, mice, and printers, that's great. If you connect your MP3 player, digital cam, etc... to the hub, things could get hairy.
Just something to think about.