Every Harmony model will be able to do what you're looking for. There's no hard-set 1:1 relationship between video and audio source selections as far as the remote configuration goes.

The "One" is by far the best looking remote they have ever produced (even if they stole my product name - Iong story). I'm not sure about its plastics because I haven't held one yet, but it's by far the best/logical layout, especially compared to many of the crappier ones they've produced, including the 880 which I have.