Try the boxes, and listen. Every Alembic I've had (Spoilers and Series) has put out low, or line-level, impedence, which means I could jack the bass straight into a power amp or mixing console and get a flat EQ sound without issues.
If your Alembic's signal is too much for your favored fuzz, try cutting the volume control to taste, or adjust the trimpots that adjust the bass' output, which accomplishes largely the same effect but is harder to accomplish on the fly.
The best dirty tone I ever got on tape (with a non-Alembic bass) was through a Bellari tube mic pre into an ADAT. I imagine one of those would work well, considering they have input gain controls to match the signal, or you could go hog-wild and use a Z. Vex Fuzz Factory or Woolly Mammoth, which have the power to level small cities and/or spur psychedelic flashbacks.
