D2 S8 servicing

[James7]

Hi

I'm looking to buy a D2 S8. Could you please help me with the following questions:

1. Is the service schedule 18K miles or 2 years?
2. When should the timing belt service be carried out? Is it either mileage or certain number of years? What should be changed at this service? Roughly how much should it cost via Audi and independant garage?
3. When should the gearbox be serviced and what is involved with this?

Any help would be much appreciated.

Thanks

James