The app runs on OSX and Linux (x86 or ARM) at this time. On the PC I use the internal sound hardware with a headset. On the Pi I have used an external sound fob (CM108) for sound (the Pi has no sound input!).
On the Pi I have done both GUI based PTT (like the video) as well as VOX. The Vox was cool because I used a HT mic with a ptt button. Because the PTT gated the audio from the mic, I never had to worry about ambient noise triggering the transmit mode. I just push the button and talk. Just like a radio, ha.
The app can use either the DV3000 or the ThumbDV in direct serial mode or via the ambe server if you wanted. I do often use AMBE server because I test on many devices and it is good to have a server when ever I need it.