On a 52 plate there were 3 versions (Base, SE and Sport). On the Sport you got 17" 9 Spoke Alloys (Base and SE had 16" with different design), Lowered suspension (20mm although I think all Quattros had this regardless of spec), Fully [painted bumpers and sills (Base and SE had dark gray lower bumpers and sills regardless of body colour), Sports from seats with electric lumber control. On the SE you got DIS, Front Centre Armrest and Cruise Control, all of which were optional on the Sport. Leather was an option but ESP was standard across the range. Other common options at the time were the upgrade from the standard Concert II radio/cd to the Symphony II radio/cd with inbuilt autochanger/cassette and rear parking sensors
Hope that helps (had an 03 1.8T Sport Saloon for 6 years from new, now have a c6 2.0 TDIe Avant)