hi, im a newbie who's jus bought an imola yellow s3. (gr8 car!

)
planning to upgrade the wheels to 18/19" but people only want to sell me rims with an offset of 33mm (standard golf/a3 i think).
not wide enough for my car because of the slighty wider arches on the quattro.
can anyone help by telling me the correct offset and width i need to fill the arches properly and look good!?