spacer advice

hi, so i picked up a volvo 940 about 3 weeks ago now and was going to go for a set of banded steels but gone off the idea now and won a set of borbet a's in a 16" 7.5j with a et 30 offset, now what i need the advice on is the thickness of the pdc adaptors im going to buy to fit them on the car, a 30 mm pdc adapter would bring the wheels to a et0 offset would this make the wheels sit nice in the arches (would like them as close to the arch as possible without causeing rubbing issues with the tyres) dont mind a slight stretch on the tyres but nothing mad would like to avoid doing any arch work if possible. thanks for any help

heres a pic of the wheels