Gregory, IF and when you get a lo-pass cab, be sure and get a 4-ohm cab. This way, you'd end up with a 4-ohm cab on the deep end, and an 8-ohm cab for the high side.
Remember you want more juice in the subs, and this would automatically prompt the amp into a higher output on the deep end.
Like our basses, this sort of thing may not be for everyone. Lots of guys are fat and happy and sound fine with an SVT and a Jazz. However, once you hear a good preamp coupled to a commercial power amp, the obvious difference in warmth, cleanliness, and headroom can be quite a welcome improvement. And, these days, with the one-space lightweight amps, we don't have the weight penalties I once had with a CS800 or similar transformer-based power amps. CA Crests, P-series Yamahas, all great amps, but NOT lightweight power. The thought of Demeter's preamps incorporating an 800-watt power section inside a single rack space chassis almost seems like science fiction after living through the 70's and 80's.
See, there you were minding your own business, and then you bought this used Alembic . . . . we've all seen this movie . . . .
Joey