Graham,
I think you would do great for Dark & Deep with ANY Alembic, however, the Europa and Rogue model electronics have the quick change switches, and the bass boost is incredible! It's a 3 position switch, and at the boost +6db, an 18 sub really rattles the walls! For ultimate deep bass: Neck-thru, ebony neck laminates, & 35 scale length or longer. But alas, you won't find these options on the second hand market - maybe once in a blue moon, and not cheap EVER! Try to find a rogue or Europa with model electronics, and 18 boxes for best boom!
Kris.