I need to control some USB smartcard readers from a virtual machine (linux), can you recommend a device with good drivers to let the VM see the physical USB devices connected like a physical computer?
If I understand you correctly, you're looking for a device with at least one USB port. Any USB device connected to that ”hub“ will be ”shared“ to the VM. If that's the case, I suggest you to search the internet for the following word combinations:
USB over IP
USB over ethernet
ethernet USB device server
ethernet USB sharing station