Arthur Barrow's website: http://home.netcom.com/~bigear/
He's got a whole section on his Zappa days, including the "Yellow Snow..." live track where he was sick and had to have a bucket next to him on stage (there's also a track on the album where Zappa introduces the band, along with their various ailments).
I got to see Arthur and Tommy Mars (ex Zappa keyboardist) earlier this year when the music department at the University of North Texas brought them in to do a concernt with the students. One of the music professors teaches a survey course on Zappa's music. They sounded great, and it was a trip watching Mars play on a huge Hammond/Leslie organ in a little recital hall.