I use raop-play
I mainly run debian unstable and got it work on my laptop with ubuntu junky ;-) as well ... I run the stand-alone client raop_play, not the alsa device.
I got the sound device to compile with my kernel, however, I never got the alsa sound device to work ... programs complain it is no alsa sound device ...
So what I do is the following:
raop_play airport_express_ip ~/sound.wav &
in vlc I set output to the file: ~/sound.wav
Everything I play through vlc now plays on the speakers ... I have to restart both vlc or raop_play about every 5 hours or so, because one of them seems to have a problem after some time (raop disconnects or vlc hangs) ... not really a big issue, though ... I use it all day long every workday ... ;-)
It is more reliable than iTunes, which just stops sending the audio to the airtunes every 5 to 10 songs ... I think my airtunes maybe to blame, but raop manages much longer connections
Have you tried airfoil in wine?