The Focus 12 looks like a fairly standard 12" bass cab to me. It certainly looks smart and would probably benefit from a driver upgrade. 200 watts was great twenty years ago but today it signals a cheap driver. Even the bottom-of-the-range Eminence Betas are 250 watts.
Obviously, it would be nice to know the internal volume, but assuming that Genz Benz have done their homework, any 12" driver designed with bass guitar in mind will work. The porting looks like it will handle more powerful drivers. I see they are plywood cabs, but what's the cabinet construction like? There's not much point installing an expensive driver in a cheaply constructed box.