What might work is buy a b&o playmaker and connect the 8000's to that.
Than sign up for itunes match. You will than have all you music available on iphone and ipad, and you can stream the music to the playmaker from that.
Another solution is to buy a sonos:connect and connect the 8000's to that via cinch cable. That works very well, and you can control the sonos from every computer or iphone/ipad. You also have spotify, internet radio, basically every service you will need.
I see no easy way to connect the 8000s to an appletv. You can however connect them to your tv in most cases. If you like the user interface of the apple tv this might work very well.
I would not connect the 8000s directly to an airport express. Sound quality is poor. Volume control mighnt be possible. I don't know. I have connected the airport to amplifiers in the past, but never to active speakers. I don't think this is possible without extra boxes.
I have been unable to get the palymaker working without dropouts or other network connectivity issues so I have migrated to Sonos. But others are very happy with their playmakers. There's no real price difference.