Acer sells bearings individually.
Associated uses "standard" bearing sizes for all of its kits. For instance, the wheel/hub bearings are all the same in the TC4 and B4/T4. The Differential outdrive bearings are also the same. I'm not sure, but I would not bet against it, the bearings inside of the diffs are probably the same as well. In all three kits, these bearings populate nearly the entire list of bearings in the kits.
The only different bearings in the cars are the steering rack bearings, and frankly, ceramic bearings are a complete waste for a steering rack. If I bought a kit, I would ask for extra wheel/hub bearings instead of the rack bearings (they charge the same price for all their bearings).