Here is the list of the Season 4 of the Fourth Doctor Adventures from Big Finish. And they just keep getting better and better!
4.1 - The Exxilons 
4.2 - The Darkness of Glass
4.3 - Requiem for the Rocket Men
4.4 - Death Match
4.5 - Suburban Hell
4.6 - The Cloisters of Terror
4.7 - The Fate of Krelos
4.8 - Return to Telos