No idea where you'll find an HPNA card for the Rio Receiver but you might want to look around in the Turtlebeach AudioTron forums. I believe the US model comes with a HPNA interface. Yes... I know they're not Empeg but it's the first thing I can think of that has HPNA as well

If you wanted to use a wireless network then you'll need to buy a Wireless Access Point/Bridge and set it to bridging mode and plug it into the Rio ethernet port. It's not an internal add on.