Hi Stefano, your project sounds interesting. I think you can do step 2 with the Pi but you’ll need to find a USB GPRS modem that supports ARM Linux drivers. I have no idea about that though. Also, I found the soundcard I bought not to be very stable: at times the driver seems to crash and the streaming stops. Unfortunately I have very little time to debug this. I’m considering shopping for a board that has native audio input and similar cost.