I need some advice buying a 3.0 TDI

[ChronowerX_GT]

Hi, I'm very interested in getting a 3.0 TDI as my next car, so I'm on here doing some research so I know what to look out for. 

From what I gather, it seems a fairly reliable engine and don't cost too much nowadays. My ideal model would be an automatic avant. Is there any general things I should be looking out for when buying, bearing in mind that the car is going to be 10 years old with 100k+ miles on it? The torque figures are one of the main selling points to me but I'm slightly worried about what stress this puts on things like the clutch, flywheel, driveshafts, etc. Is this a problem on these cars (especially if I remap it) and what would a new clutch/flywheel cost to stick in it?

In addition, is there any general problems with B7's in particular (suspension, steering, rust, etc)?

Any advice is welcome since this would be my first Audi. Thanks, Luke.