Alembic pickups and preamps are designed to work as a system. I know of people that have mixed and mitched, but it's not something that we offer support on, we have no direct experience.
The best instrument to use an Alembic system on is one where you like the unamplified sound. Since we don't use pickups as tone controls, you have to like the general sound of the bass. If the bass sounds good until you plug it in, the Activators will probably do nicely.
What I have now are the MM4 string pickups. You can install an AE-3 system with bass and treble controls, the volume control and the output jack on the faceplate of the bass. If you want to keep the jack sidemounted, you can add a filter control (there isn't anything to pan with just one pickup, sorry for any confusion there). I am working on a useful midgrange control for this system with my dad. With some other interesting projects we're working on, I don't think it will get enough attention to be completed until near the end of this year.