I'm looking for something that will generate a playlist combining podcasts and music (bonus points: audible books)

I would like the podcasts to delete after listening, but would like to throw some music in between podcasts as well.
i.e. podcast 1, song 1, song 2, song 3, podcast 2, song 4, song 5, song 6, etc.

The podcasts would update each time the playlist plays. The songs would be randomly selected so that they wouldn't be in the same order each time.
I use BeyondPod currently for my podcasts, and it's smartplay feature is programable enough to make me happy, but I would like something that would automatically switch to the next app to play the music.

I would love for it to throw in a chapter of the current audiobook I'm on as well (that is probably beyond the scope of this).

Does anyone know of an app that will do this?

Sorry if this doesn't make any sense.