Hi Ulf,
Welcome to the club!
Everyone has a favorite string & there are so many to choose from. It really is a personal preference, yet some strings DO sound better on an Alembic. The original Alembic strings are really good and Alembic sets up their guitars to perform best with them. Being a pressure wound string, it is a balance between a round and flat wound string. Hard to describe, but my fingers like the feel, and my ears like the sound. However, if you are ordering a new Alembic from the factory, you can specify your favorite string, and they will set it up with that set. Contact your dealer for more info about this.
What type of music do you play, and what type of string typically have you used in the past? Also, what brand of bass did you use before Alembic? All these things will play in how you want your Alembic to sound, and should help you narrow down the selection. There may not be a perfect string either, nor will you be able to try them all. Happy hunting!
Kris