After searching forum and brochure (do correct me if I'm wrong):

Sport suspension = stiffer springs (-??mm)
S Line suspension = standard shocks but -10mm/-20mm springs over stock ride height
S Sports suspension (standard on S5 and not available on std models) = different shocks and spring, includes anti roll bar, different axel etc

[from audi: Depending on the model line, your Audi with optional sports suspension is between 10 and 20 millimetres lower than with normal suspension.) For Europe do you know which one we get? The dealer does not

Question: I've got S Line suspension as part of my sline spec on an A5 coupe and so if I want to drop it further (I'm quite partial to this Audi S5 on 20'' Vossen VVS-CV7 Concave Wheels | Rims - YouTube what springs would I need and would a coilover kit be the better option?

I put KW V1 Inox on my cupra wth 18s and the ride quality was awful. With 20s (which until now I've never wanted but seem to have fallen in love with the Vossen) I'm worried about severely butchering a lovely ride. Out of the factory its coming on 18s and I will keep those as winter wheels.