Advice Sought A6 Engines and Multitronic

[ADBS65]

Hi, I am hoping that you will be able to advise me, as i am looking to buy my first Audi. I am looking at A6 primarily, although would not discount an A4. I currently average 10k per annum, generally communting with a few longer journeys per month thrown in. I only need to seat 5 adults on a rare occasion, usually there is only 2 of us in the car. I am looking at a 2008 model year 2.0ltr diesels with mutlitronic and around 70-80k miles. I have read about timing chain issues, which I think were on the C5 series but have been sorted now by the use of gear drive? I have also read about the hex drive to the oil pump failing, I am not so sure if this would affect the vehicles I am looking at. On this and other forums, it appears that the multitronic is OK, if you change the oil regularly, but if they go wrong they are a £4000 repair!
I know it is a lot to ask on my first post, but what would you advise. Is the 2.0ltr diesel in 2008 a solid engine and should I look to a manual gearbox and avoid the multitronic? Any other advice welcome.

Thanks
Andy