The PCI capture cards are pretty hit and miss when used with iCamSource. We have heard a few reports of success, but we've heard even more reports of failure with PCI cards. It all comes down to whether the drivers let the operating system know that a camera is connected. iCamSource asks the operating system for a list of connected webcams, so if the operating system doesn't know about the cameras, then iCamSource won't either.
We've heard similar reports about USB dongles. Some of them show up as webcams, and some of them don't. Hopefully the devices you ordered will be recognized by the operating system as webcams. If they aren't, make sure you have the latest drivers for the USB dongle installed.