Gasoline pump 4.2 6 gear

Hello.

I am finally proud of an Audi V8 and need a new gasoline pump. Is it true that this is in the tank? Are there differences between different versions of the petrol pump?

what should be a functional control unit for the cruise control at about cost, what the gasoline pump, both used? and ne el. Antenna?

Does it make sense to build a used differential?

would be very grateful for quick answers.