[s-cars] transmissions for sale?

[Bill Clancy]

My 5 speed transmission (95 S6) is making some noise.   My friendly mechanic looked at it today and believes it is the final drive.    It sort of sounds like a bearing noise and when it's cold it clicks.    The noise is the same in any gear or in neutral and when rolling.   

So... I think that means I need to find a transmission.   ;-(    
Does anyone have any suggestions on how to repair it?    Or where to get a used transmission?   

any help would be greatly appreciated.
thanks,
-Bill