The voices on public media like radio and TV are not representative of the general population. Sometimes ( in English language media) they do represent particular styles that are in favour. For example, 30 years ago in my country, some broadcasters spoke with a distinct English accent. I believe that the Arab media speak a stylized Arabic that is recognizable by everyone, but would be regarded as quaint if you used it in everyday speech.
But if you were going to choose an accent to focus on, for a UK accent, I would find and listen to a speaker from the BBC media.
For a US accent, I would find some audio of Walter Cronkite speaking, he was a well known presenter and many (particularly older Americans) would be react well to that accent.