People and stores keep confusing the springs for GTIs.
Europe and USA aren't comparable markets since the factory springs differ as well. American GTI have an higher ride height.
There's just one part number for European GTIs from H&R: (29176-1). They drop 30 mm from factory ride height (GTI are -20 mm compared with normal Golfs) and they look basically the same as the Eibach Sportlines, but they give a more balanced ride height between axles. The springs have an unique colour: blue, not red like the H&R -50 mm for non-GTI/GT/GT Sport mk5 Golfs.
Eibach only sells Sportlines in Europe for GTIs. There are 2 part numbers for all mk5s: with or without DSG. They are red. The rear axle sits higher compared with the H&R -30 mm.
Eibach sells Pro-Kit springs in the USA for GTIs, they are black and would only lower the European factory ride height by around 10-15 mm. I have Pro-Kits for Golfs 1.9 TDI without DSG in my GT Sport. They are really comfortable springs, much better than factory sport springs.
I had Eibach Sportlines with factory dampers in my Edition 30 and I found them too harsh over small road creases. I bet they would work much better with Bilsteins B8. I prefer the stance that H&R -30 mm give so I replaced the Sportlines and fitted Koni Sport dampers with the H&R. The setup is soo much better and has much more suppleness than before. I like it.