The software only version of Mobile PC does not come with a GPS (20x or 10x). It will work with any NMEA (that is - standard) GPS and can talk directly to Bluetooth ones if you are using the Microsoft, Broadcom or Toshiba stacks. GPS Gate can also talk directly to Bluetooth GPS devices if you are using the Microsoft or Broadcom Bluetooth stacks. In other words, if GPS Gate can see it, Mobile PC should be able to (not at the same time, of course).
I assume, if you got Mobile PC to work with a USB GPS18, it can recognize Garmin PVT also as that is all the GPS18 can do. But, I know it works fine with standard non Garmin GPS devices. Come to think of it, Mobile PC probably uses PVT with the Garmin 10x too as it can read the serial number, even in the software version.
Terry