Ish-Man,
If you are talking about red springs from IAP, those are specifically for GTV and Spider. Berlina's are heavier on the rear so therefore you will need different springs. I am little surprised and curious how those springs are working.
Alfa Ricambi is The only place that have them. You will find Berlina springs that are specifically made for the car.
The best set up will be Red Koni's all around adjustments, 30% front & 10% rear, with AR springs.
I had Bilstein on my Berlina and did not like the setup, little harsh.
Again I might be wrong, but that's what everyone suggested including IAP, Centerline.
That's what I have on my car with 15x6 Panasport 195/55/15 tires.
Giorgio