Apple Logic Pro /LogicExpress Discussion

I want to gradually fade in 8 vocal tracks (a choir) at the beginning  
of my song.  My first thought is to route them all through a bus and  
fade the bus in.  However, I can't figure out how to get my busses on  
to the arrange window so I can apply track automation.   I then  
thought of routing them through an aux, but my auxes don't show up in  
the output drop down on my channel strips.   I'd rather not put in  
the same volume automation for 8 tracks, as the tweaking would get a  
bit cumbersome.  Is there a solution out there?

Thanks,

Gregory