Bilstein B8s are probably the best match for the springs, and the most widely used. The ride with just lowering springs and standard dampers is not very good - bouncy, bouncy.
The stance is good though, looks a million times better than standard ride height. Had my springs taken off today, back to off-road mode for selling the car
. If you're after a set of springs, PM me.
No problems with rubbing with 10mm front/12mm rear spacers on 18" S3 wheels (7.5" wide, ET56 without spacers). Also no issues with my 19" Speedlines (8.5" wide, ET48 and had 4mm spacers on the front too).