I have a 2003 325xi sedan. I spent almost 3 months looking into my suspension upgrade. The XI is a complete different setup than the 2wd version. Ride height and ride quality options are very limited on this car.
From other BMW owners and mechanics in my area I was clearly warned that the H&R with bilstein setup will be to harsh and stiff for the NYC area. That the best option was the Eibach and Koni combination. My rear springs were broken, I knew of the rear passenger side being broken, when I did the install we found the other rear spring was also broken. The thing with the Koni's is that they are usually on back order or out of stock, even the Bilstein's are in limited supply. This car has a particular strut/shock fitment that is not always available. I don't like harsh rides, and I'm very pleased with the Eibach Koni combination on my car, I'm going to play around with the Koni adjustment this week to see what the differences feel like. That's the other thing, based on your original post and comments I think the Eibach / Koni combo will be a good combination for you. The fact that the Koni's are adjustable is a plus.
So far I've done the front control arm bushings (rear bushings on the front control arm), all 4 Eibach's and the front Koni's. The rear Koni's just arrived and I'll be doing the shock mounts with those, it's another E46 weak point, might as well do it now and save on labor.