I was going to originally recommend using raspberryPi, though as you want a radio and OTA tv tuner I don't believe that device would work for you anymore.
I may have a couple additional ideas, though let me research them a bit before potentially pointing you down the wrong hiking path.
Quick Update: Something like this may work:
AVerMedia AVerTV Global - TV Tuners, Live IPTV Streaming Encoder, Video Capture Card, Media Player and Multimedia Products - AVerTV Ultra PCI-E RDS they have usb and internal versions of it too.