Wireless music conundrum

I'm having trouble sorting out the options here and could use some help.

My wife has an iPhone, and will probably have an iPad soon. I have two Android Nexus devices (phone and tablet). We'd like a solution that allows us to play music from our library on our entertainment system, either via the cloud or wirelessly from our devices.

My challenges, in decreasing order of priority:

  • Maintaining access to our music library from any of our mobile devices, and potentially whatever device we put into the entertainment center.
  • Controlling music playback through the entertainment system in real time from our mobile devices.
  • Maintaining a library, either locally or (preferably) in the cloud, that allows my wife to use iTunes, and allows me to use others like Amazon or Google Play.
  • It would also be nice to be able to play movies rented from Amazon Unbox, as well as other services like iTunes, on the TV.

What combination of cloud service, entertainment device, and smartphone apps can I use to realize this dream, while maximizing the all important WAF? Please help!