Break and disc upgrade

[olu]

Hi everyone,

I need advice on upgrading my A6 Avant C8. I'm looking to replace my 20-inch alloy wheels (255/40 R20 Y XL) with 21-inch wheels. The alloy wheel company suggested RS6 21-inch wheels with an ET35 offset and a 5mm spacer to clear the brakes. However, both Audi and some other sources advised against the ET35 offset. When I went back to the alloy wheel company, they recommended an ET30 fitment instead. For reference, my current 20-inch wheels are labeled E8.5J×20 H2 ET43.

I'm also planning to upgrade my brake discs and calipers to a larger size, aiming for an RS6-like appearance. Can anyone advise on the appropriate size for the brakes and calipers? Has anyone done this upgrade? If so, what size did you choose?