I wouldn't bother going and paying dealer prices for the standard Abarth springs, as long as you're patient they do come up on occasion for not a lot of money - I sold some on here about a month ago for £30+p&p.
I cannot comment on essesse spring drop, I have eibach pro's on mine at the moment but I did briefly try the stock abarth's just on the rear and they were about 18-20mm higher.
If I were to order them in highest to lowest I'd probably go:
Stock GP - Sporting GP - Abarth 155 - Proline - Essesse - Sportline
the only one I'm not sure on is the position of the Essesse's in comparison to the Pro's.
I do find my pro's a touch lower on the rear when comparing the arch gap front to back, though that could be due to carrying a full spare sporting alloy and sub in the boot. Looking to go back to full Sportline's now that my office has moved location and the roads on my commute are in much better condition.