If you want to get jaw surgery at some point, then you should not be trying to have your orthodontist correct your overbite through orthodontic compensation. Instead, your orthodontist should attempt to position your teeth in the ideal alignment for each jaw, independent of the overall occlusion. For a class 2 case, this typically involves resolving mandibular crowding, uprighting and retracting the lower incisors, and slightly flaring the upper incisors. Since you have 6 months before your consultation, your orthodontist can likely complete all or most of this decompensation. Make sure to tell him that you are committed to jaw surgery.