Ok, think I need to get my anal-ness on and clear this up:
172 Phase 2:
Leather interior, Xenon headlamps, auto headlamps, auto wipers, Climate control. Some very late ones had cruise control.
172 Phase 2 Cup:
Cloth interior, Halogen lights, manual lights (wipers too I think), no ABS, no climate control, Wider track from different wheels, 90KG lighter than the standard 172.
182:
All the features of the late standard 172, plus 10-ish bhp more, twin exhaust, no spare wheel, 20kg lighter than the 172.
182 Cup:
A 182 without leather, climate, cruise, abs or auto lights (wipers?). BUT, the cup had different (firmer, lower, wider) suspension, a front splitter, and a larger rear spoiler.
Then the messy bit:
Cup Handling Pack - an option to add the 182 Cup suspension to a standard 182
Cup Styling Pack - an option to add the 182 splitter and larger wing to a standard 182
182 Full Fat - an internet name for a standard 182 with both Cup packs.
So in essence, the 172 Cup is a 172 with stuff taken away, while the 182 Cup has stuff taken away other things added and changed, and a 182 FF is the best of everything.
Therefore, if you want a 172, then you want the standard car. If you want a 182, then you want a Full Fat.
Edit: Unless your are going to 'do an alexisonfire' and strip it out, in which case you wont want any of the creature comforts so might want to get a 172 Cup (and arrange your last will and testament, as they have no ABS).