Can anyone tell me if the doors from an A4 B5 saloon are compatable with the avant?
yes, but you'll need to transfer the window frame over from the old door.
2000 A4 1.8T Sport Quattro Avant, Berry Pearl
2000 A4 1.8T Sport Quattro Saloon, Black-ish
1997 S4 - PPC £999 Challenge Track Car Build
TD5 Land Rover Defender build
Lovely... Shouldn't be too hard!