2006 4.2 tdI rear disk rear pads front pads:questions

[goldsax]

need some advice please
called an Audi indie yesterday re. cost of F/R pads only replacement.
they said that the rear disks were lipped and would also need to be changed.
total cost £780
to me that sounds a lot.
i am aware that the 4.2TDi has larger disks and pads.
looking at ebay and eurocarparts they have varing sizes.
and the process also will need VAGCOM for rear reset.
any idea what size ( parts) i need?
any idea where a VAGCOm competent garage/indie/person may be able to do it? does it have to be Audi? can a VW garage do it.

i hope i dont come across as trying to work to an unrealistically small budget. but £780 is a lot of money esp when i can buy quality parts for approx £350( i presume)
I am in Leicestershire
many thanks raj