Assuming you have the rights to the radio shows and any ads runinng in the shows
I would use http://gabcast.com/
there is a gabcast module which can used and exten’s be mapped to gabcast channels, update the channel, update the show. Plus no load on your PBX to play the shows. You will have to pay some funds to Gabcast but Hey Coalescent Systems
is kinda the reason we are here.