IIRC, the early hubs (84-89) are much easier to find bearing to install than the later ones, but I've not tried to source any-- I'm more comfortable knowing the "other" parts are new and not worn/ damaged.
obviously, it's "possible", as it is just the sum of all the parts that make up the hub, but often the inner and outer parts will suffer wear if the bearing fails, but the parts could very well be equally as costly as the assembly once you source them separately.