Damager

not long picked up an e39 528i and wanting to ditch the factory alloys. was looking at putting on 18s, but having a hard time finding used sets with 20p offset. seems to be truckloads for 1 and 3 series with varying offsets but not many for 5 series with 20p? following the book it says 20p offset for 18/8 , so my search is based only on that info. can a 24 or 18 offset go also? maybe stay 17s? suggestions welcome!