If the ignition coils are working fine, there's no real need to replace them. They'll generate misfire codes when they fail.
However, I would trust an NGK replacement just fine.
48082 is the correct coil for the 5V 4.2.
Genuine Audi coils at FCP Euro are US$40 ea. I thought they were Bosch, but I cannot find an Audi coil in the Bosch catalogue, so I have no other brand suggestions.
If you stick with NGK, same coil at a lower price
here